[chore] Android: move namespace declaration

[timokz]

Description

One Line Summary

Enables building apps with agp =< 8.0

Details

Motivation

As this helpful PR already attempted, for apps using Gradle 8.0 or greater, moving the namespace declaration from the AndroidManifest.xml files is necessary. The other PR has a minor syntax error and doesnt delete the conflicting declaration in the xml files.

Otherwise developers will be confronted with this error:

* What went wrong:
A problem occurred evaluating root project 'android'.
> A problem occurred configuring project ':app'.
   > Could not create an instance of type com.android.build.api.variant.impl.ApplicationVariantImpl.
      > Namespace not specified. Please specify a namespace in the module's build.gradle file like so:

        android {
            namespace 'com.example.namespace'
        }

        If the package attribute is specified in the source AndroidManifest.xml, it can be migrated automatically to the namespace value in the build.gradle file using the AGP Upgrade Assistant; please refer to https://developer.android.com/studio/build/agp-upgrade-assistant for more information.

Or other, more obscure warnings thrown by the gradle wrapper.

Scope

None of the actual source is changed, the changes are contained to the android directory of the package and the example app.

Other

I've also updated the AndroidManifest.xml files to have their namespace declaration, e.g. package="com.onesignal.onesignalexample" in the <manifest> tag removed, as the AGP upgrade agent would also refactor to be in line with the newer gradle versions.

Manual testing

Tested building the example and my own app, using flutter sdks 3.16.5 and 3.13.0, respectively. All features in the example app work as intended. They also shouldn't be affected by my changes.

Affected code checklist

• [ ] Notifications
  • [ ] Display
  • [ ] Open
  • [ ] Push Processing
  • [ ] Confirm Deliveries
• [ ] Outcomes
• [ ] Sessions
• [ ] In-App Messaging
• [ ] REST API requests
• [ ] Public API changes

None apply, buildscripts are affected.

Checklist

Overview

• [x] I have filled out all REQUIRED sections above
• [x] PR does one thing
• [x] Any Public API changes are explained in the PR details and conform to existing APIs

Testing

• [x] I have included test coverage for these changes, or explained why they are not needed
• [x] All automated tests pass, or I explained why that is not possible
• [x] I have personally tested this on my device, or explained why that is not possible

Final pass

• [x] Code is as readable as possible.
• [x] I have reviewed this PR myself, ensuring it meets each checklist item

---

This change is 

[Raph0007]

lgtm 👍🏻

[NinoBass]

Hey @timokz Check in the android/build.gradle file, I think it should be com.onesignal.flutter and not com.onesignal.onesignalexample

[nan-li]

Hi @timokz thank you for submitting this PR, we did approve a contributor's PR for this same issue.

Is the removal of the package name in the Android Manifest file necessary?

[timokz]

Hey @nan-li thanks for the maintenance! Now I can go back to using the original dependence.

Regarding the manifest files: It is recommended and also applied by the AGP upgrade assistant . My pr also includes the upgrade for the example project.

You can verify that by running the assistant in a project of yours or (not ideal) checking this screenshot in the official docs

[nan-li]

Regarding the manifest files: It is recommended and also applied by the AGP upgrade assistant . My pr also includes the upgrade for the example project.

You can verify that by running the assistant in a project of yours or (not ideal) checking this screenshot in the official docs

Ahh ok, thank you @timokz , I understand!

I don't think we are ready to port our projects over to AGP 8, since it will certainly break some colleagues' setups.

We have released the namespace support for the OneSignal Flutter SDK on both Release 3.5.2 and Release 5.1.0, so I will close this PR.

Thanks again for submitting this PR!