RUM-4260 Make CoreTracer code Java 7 compatible

[mariusc83]

What does this PR do?

In this PR we are cleaning up the imported Java code for the CoreTracer and make it Java 7 compatible in order to not require desugaring on Android 23 and below.

The are several steps in achieving this:

• we are adding back the Injectors into the CoreTracer as I realized that we will be needing this later for Context propagation
• we are replacing the logic where java.util.Base64, java.util.Map, java.util.Stream is being used in order to make it Java 7 compatible
• for the places where we cannot delete or replace would be too complex we are introducing our own package with substitutes for this lambda functions
• we are performing more cleaning after and re - enabling the NewApi rule for linting

Have in mind that maybe some more cleaning could be performed but I don't find this idea wise. What I could clean so far was code that I was really certain that it cannot affect the current functionality, it will not have any impact on the APM metrics and will not have repercussions later. We already went into trouble by removing the Injector which seemed not to be used for the moment and I just realized during this PR work that this will have a negative impact later.

Motivation

What inspired you to submit this pull request?

Additional Notes

I performed a Profiling by analyzing the CPU consumption and Memory consumption while using the new Otel code and I could not see any potential issue (spike).

Review checklist (to be filled by reviewers)

• [ ] Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• [ ] Make sure you discussed the feature or bugfix with the maintaining team in an Issue
• [ ] Make sure each commit and the PR mention the Issue number (cf the CONTRIBUTING doc)

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 34.22460% with 369 lines in your changes are missing coverage. Please review.

Project coverage is 66.82%. Comparing base (ad06c50) to head (da0a254). Report is 1 commits behind head on feature/otel-support.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## feature/otel-support #2051 +/- ## ======================================================== + Coverage 64.11% 66.82% +2.70% ======================================================== Files 759 734 -25 Lines 28307 27197 -1110 Branches 4753 4603 -150 ======================================================== + Hits 18148 18172 +24 + Misses 8926 7798 -1128 + Partials 1233 1227 -6 ``` | [Files](https://app.codecov.io/gh/DataDog/dd-sdk-android/pull/2051?dropdown=coverage&src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=DataDog) | Coverage Δ | | |---|---|---| | [...ce/src/main/java/com/datadog/trace/api/Config.java](https://app.codecov.io/gh/DataDog/dd-sdk-android/pull/2051?src=pr&el=tree&filepath=features%2Fdd-sdk-android-trace%2Fsrc%2Fmain%2Fjava%2Fcom%2Fdatadog%2Ftrace%2Fapi%2FConfig.java&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=DataDog#diff-ZmVhdHVyZXMvZGQtc2RrLWFuZHJvaWQtdHJhY2Uvc3JjL21haW4vamF2YS9jb20vZGF0YWRvZy90cmFjZS9hcGkvQ29uZmlnLmphdmE=) | `59.00% <ø> (+12.62%)` | :arrow_up: | | [...main/java/com/datadog/trace/api/DynamicConfig.java](https://app.codecov.io/gh/DataDog/dd-sdk-android/pull/2051?src=pr&el=tree&filepath=features%2Fdd-sdk-android-trace%2Fsrc%2Fmain%2Fjava%2Fcom%2Fdatadog%2Ftrace%2Fapi%2FDynamicConfig.java&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=DataDog#diff-ZmVhdHVyZXMvZGQtc2RrLWFuZHJvaWQtdHJhY2Uvc3JjL21haW4vamF2YS9jb20vZGF0YWRvZy90cmFjZS9hcGkvRHluYW1pY0NvbmZpZy5qYXZh) | `55.75% <ø> (ø)` | | | [.../main/java/com/datadog/trace/api/EventTracker.java](https://app.codecov.io/gh/DataDog/dd-sdk-android/pull/2051?src=pr&el=tree&filepath=features%2Fdd-sdk-android-trace%2Fsrc%2Fmain%2Fjava%2Fcom%2Fdatadog%2Ftrace%2Fapi%2FEventTracker.java&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=DataDog#diff-ZmVhdHVyZXMvZGQtc2RrLWFuZHJvaWQtdHJhY2Uvc3JjL21haW4vamF2YS9jb20vZGF0YWRvZy90cmFjZS9hcGkvRXZlbnRUcmFja2VyLmphdmE=) | `0.00% <ø> (ø)` | | | [...src/main/java/com/datadog/trace/api/Functions.java](https://app.codecov.io/gh/DataDog/dd-sdk-android/pull/2051?src=pr&el=tree&filepath=features%2Fdd-sdk-android-trace%2Fsrc%2Fmain%2Fjava%2Fcom%2Fdatadog%2Ftrace%2Fapi%2FFunctions.java&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=DataDog#diff-ZmVhdHVyZXMvZGQtc2RrLWFuZHJvaWQtdHJhY2Uvc3JjL21haW4vamF2YS9jb20vZGF0YWRvZy90cmFjZS9hcGkvRnVuY3Rpb25zLmphdmE=) | `25.00% <ø> (+21.88%)` | :arrow_up: | | [.../main/java/com/datadog/trace/api/GlobalTracer.java](https://app.codecov.io/gh/DataDog/dd-sdk-android/pull/2051?src=pr&el=tree&filepath=features%2Fdd-sdk-android-trace%2Fsrc%2Fmain%2Fjava%2Fcom%2Fdatadog%2Ftrace%2Fapi%2FGlobalTracer.java&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=DataDog#diff-ZmVhdHVyZXMvZGQtc2RrLWFuZHJvaWQtdHJhY2Uvc3JjL21haW4vamF2YS9jb20vZGF0YWRvZy90cmFjZS9hcGkvR2xvYmFsVHJhY2VyLmphdmE=) | `0.00% <ø> (ø)` | | | [...ain/java/com/datadog/trace/api/cache/DDCaches.java](https://app.codecov.io/gh/DataDog/dd-sdk-android/pull/2051?src=pr&el=tree&filepath=features%2Fdd-sdk-android-trace%2Fsrc%2Fmain%2Fjava%2Fcom%2Fdatadog%2Ftrace%2Fapi%2Fcache%2FDDCaches.java&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=DataDog#diff-ZmVhdHVyZXMvZGQtc2RrLWFuZHJvaWQtdHJhY2Uvc3JjL21haW4vamF2YS9jb20vZGF0YWRvZy90cmFjZS9hcGkvY2FjaGUvRERDYWNoZXMuamF2YQ==) | `100.00% <ø> (+71.43%)` | :arrow_up: | | [...va/com/datadog/trace/api/cache/FixedSizeCache.java](https://app.codecov.io/gh/DataDog/dd-sdk-android/pull/2051?src=pr&el=tree&filepath=features%2Fdd-sdk-android-trace%2Fsrc%2Fmain%2Fjava%2Fcom%2Fdatadog%2Ftrace%2Fapi%2Fcache%2FFixedSizeCache.java&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=DataDog#diff-ZmVhdHVyZXMvZGQtc2RrLWFuZHJvaWQtdHJhY2Uvc3JjL21haW4vamF2YS9jb20vZGF0YWRvZy90cmFjZS9hcGkvY2FjaGUvRml4ZWRTaXplQ2FjaGUuamF2YQ==) | `44.44% <ø> (ø)` | | | [...va/com/datadog/trace/api/cache/RadixTreeCache.java](https://app.codecov.io/gh/DataDog/dd-sdk-android/pull/2051?src=pr&el=tree&filepath=features%2Fdd-sdk-android-trace%2Fsrc%2Fmain%2Fjava%2Fcom%2Fdatadog%2Ftrace%2Fapi%2Fcache%2FRadixTreeCache.java&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=DataDog#diff-ZmVhdHVyZXMvZGQtc2RrLWFuZHJvaWQtdHJhY2Uvc3JjL21haW4vamF2YS9jb20vZGF0YWRvZy90cmFjZS9hcGkvY2FjaGUvUmFkaXhUcmVlQ2FjaGUuamF2YQ==) | `0.00% <ø> (ø)` | | | [...race/api/experimental/DataStreamsCheckpointer.java](https://app.codecov.io/gh/DataDog/dd-sdk-android/pull/2051?src=pr&el=tree&filepath=features%2Fdd-sdk-android-trace%2Fsrc%2Fmain%2Fjava%2Fcom%2Fdatadog%2Ftrace%2Fapi%2Fexperimental%2FDataStreamsCheckpointer.java&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=DataDog#diff-ZmVhdHVyZXMvZGQtc2RrLWFuZHJvaWQtdHJhY2Uvc3JjL21haW4vamF2YS9jb20vZGF0YWRvZy90cmFjZS9hcGkvZXhwZXJpbWVudGFsL0RhdGFTdHJlYW1zQ2hlY2twb2ludGVyLmphdmE=) | `0.00% <ø> (ø)` | | | [...ce/api/normalize/AntPatternHttpPathNormalizer.java](https://app.codecov.io/gh/DataDog/dd-sdk-android/pull/2051?src=pr&el=tree&filepath=features%2Fdd-sdk-android-trace%2Fsrc%2Fmain%2Fjava%2Fcom%2Fdatadog%2Ftrace%2Fapi%2Fnormalize%2FAntPatternHttpPathNormalizer.java&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=DataDog#diff-ZmVhdHVyZXMvZGQtc2RrLWFuZHJvaWQtdHJhY2Uvc3JjL21haW4vamF2YS9jb20vZGF0YWRvZy90cmFjZS9hcGkvbm9ybWFsaXplL0FudFBhdHRlcm5IdHRwUGF0aE5vcm1hbGl6ZXIuamF2YQ==) | `0.00% <ø> (ø)` | | | ... and [26 more](https://app.codecov.io/gh/DataDog/dd-sdk-android/pull/2051?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=DataDog) | | ... and [32 files with indirect coverage changes](https://app.codecov.io/gh/DataDog/dd-sdk-android/pull/2051/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=DataDog)