Install NDK 25.1.8937393 in the Docker image

[0xnm]

What does this PR do?

Build script is using NDK 25.1.8937393 while Docker contains the older one, so we were wasting some time to download the necessary NDK version during the build process.

This PR updates NDK version to the necessary one in the Docker image.

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

Merging #248 (e1f04f3) into develop (924006b) will decrease coverage by 0.08%. The diff coverage is n/a.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #248 +/- ## ============================================= - Coverage 81.50% 81.42% -0.08% - Complexity 203 204 +1 ============================================= Files 26 26 Lines 800 802 +2 Branches 103 104 +1 ============================================= + Hits 652 653 +1 Misses 112 112 - Partials 36 37 +1 ``` [see 1 file with indirect coverage changes](https://app.codecov.io/gh/DataDog/dd-sdk-android-gradle-plugin/pull/248/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=DataDog)