values-v<sdk> Android resource directories are not prepared correctly

[rosen-vladimirov]

Environment
Provide version numbers for the following components (information can be retrieved by running tns info in your project folder or by inspecting the package.json of the project):

• CLI: 6.2.0
• Cross-platform modules: Not applicable
• Android Runtime: 6.2.0
• iOS Runtime: Not applicable
• Plugin(s): Not applicable

Describe the bug
Currently all values-v directories from <path to project's App_Resources>/Android/src/main/res are included in the native project. The purpose of these directories is to separate the resources and features available for different SDKs. In case you build the application with SDK 28 for example, the resources for SDK 29 shouldn't be included in the project as probably they contain a resource usage that is not buildable with SDK28.

To Reproduce

1. Create new project: tns create appValuesIssue --js
2. Open the newly created project and copy appValuesIssue/app/App_Resources/Android/src/main/res/values-v21/ to appValuesIssue/app/App_Resources/Android/src/main/res/values-v29/
3. Build the project: tns build android --compileSdk 28
   Build fails with error:

Execution failed for task ':app:processDebugResources'.
Android resource linking failed
<project dir>\platforms\android\app\src\main\res\values-v29\styles.xml:5:5-7:13: AAPT: error: style attribute 'android:attr/forceDarkAllowed' not found.


Command gradlew.bat failed with exit code 1

4. Check the appValuesIssue/platforms/android/app/src/main/res/values-v29/ dir - it will be there, while in fact, it shouldn't.

Additional context

[rosen-vladimirov]

Acceptance criteria:

• Build with --compileSdk 28 should work.
• Build with --compileSdk 28 must not have <project dir>\platforms\android\app\src\main\res\values-v29 dir.
• Build with SDK 29 must enable dark theme support (i.e. the <project dir>\platforms\android\app\src\main\res\values-v29 dir must exist)