Parent: #17173
Closes: #17174
Associated To: #17197

This PR enables all warnings as errors for the annotations module.

This allWarningsAsErrors configuration is currently applied on the module level in order to make sure that, as the overall Compiler Warnings as Errors work is progressing, no new warnings are added to this module, which is already free of warnings.

When the overall Compiler Warnings as Errors work is complete on all modules, then this module level allWarningsAsErrors configuration will be replaced by a root level such configuration that will be applied by default to all modules (see here).

Note that, in addition to enabling the allWarningsAsErrors configuration on the annotations module, I took this opportunity to improve on other aspects of java and build related configurations. As such, this PR also improves on the following in order to mainstream this (kind of related) group of configurations, for this and all other lib module:

• java
  • java 7
    • Remove unnecessary source/target compatibility for java 7.
  • source/targetCompatibility
    • Replace source/target compatibility 1.8 with java version const.
• configuration
  • compileTestKotlin
    • Remove unnecessary compile test kotlin configuration block.
  • kotlinOptions
    • Replace kotlin options jvm target 1.8 with java version const.
    • Remove unnecessary kotlin options jvm target config from all mods.
  • compileOptions
    • Remove compile options configuration from editor libs module.
• repos
  • repositories
    • Remove maven central repositories config from annotatios module.

PS: @ovitrif I added you as the main reviewer, that is, in addition to @wordpress-mobile/apps-infrastructure team itself, but randomly, since I want someone from the WordPress Android team to primarily sign-off on that change. 🥇

FYI: I am going to randomly add more of you in those PRs that will follow, just so you become more aware of this change and how close we are on enabling allWarningsAsErrors by default everywhere. 🎉

To test:

• There is nothing much to test here.
• Verifying that all the CI checks are successful should be enough.
• However, if you want to be thorough about reviewing this change, you could test the feature flag functionality, since this annotations module, along with the processors module is responsible for that. For example, you could try switching the jetpack_powered_bottom_sheet_remote_field feature flag, on and off, and see if that works as expected.

Regression Notes

1. Potential unintended areas of impact

The feature flag functionality is not workings as expected.

2. What I did to test those areas of impact (or what existing automated tests I relied on)

See To test section above.

3. What automated tests I added (or what prevented me from doing so)

N/A

PR submission checklist:

• I have completed the Regression Notes.
• I have considered adding accessibility improvements for my changes.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.