F-Droid friendly codebase

[TranceLove]

Description

To make gradlew clean spotlessApply spotlessCheck jacocoTestFdroidDebugUnitTestReport assembleDebug build workflow also work seamlessly,

• Moved RAR related tests to testPlay directory
• CompressedHelperCallableTestSuite for different flavours
• ExtractorTestSuite for different flavours
• Added build flavour checking in CompressedHelperTest and ExtractServiceTest

Manual tests

• [x] Done

By doing a ./gradlew clean spotlessApply spotlessCheck jacocoTestFdroidDebugUnitTestReport clean spotlessApply spotlessCheck jacocoTestPlayDebugUnitTestReport assembleDebug --stacktrace that can finish without any errors. Also check RAR related tests in play flavour are run, not skipped.

Build tasks success

Successfully running following tasks on local:

• [x] ./gradlew assembledebug
• [x] ./gradlew spotlessCheck