Update build.gradle setup

[friederbluemle]

Summary

A slightly different approach to #207

This wraps the Android Gradle plugin dependency in the buildscripts section of android/build.gradle in a conditional:

if (project == rootProject) {
    // ... (dependency here)
}

The Android Gradle plugin is only required when opening the project stand-alone, not when it is included as a dependency. By doing this, the project opens correctly in Android Studio, and it can also be consumed as a native module dependency from an application project without affecting the app project (avoiding unnecessary downloads/conflicts/etc).

Test Plan

What's required for testing (prerequisites)?

Android Studio and/or Gradle installed locally.

What are the steps to reproduce (after prerequisites)?

Open android in Android Studio:

studio android/

Or:

Generate a Gradle wrapper on the fly, and build on command line:

cd android/
gradle wrapper --gradle-version 5.4.1 --distribution-type all
./gradlew build

Successfully verified and tested on:

• Android Device (Xiaomi Mi A2)
• Android Emulator (Pixel 3a)
• iOS Device (iPhone 8)
• iOS Simulator (iPhone X)

_{^{Once approved, please use a normal GitHub merge (i.e. NO rebase/squash merge) to integrate the commit(s) from the PR head branch. The changes are broken up into meaningful, atomic commits, and my branch should already be up-to-date with the latest base branch. If it isn't, or if you want me to change anything, please let me know, and I will update the branch as soon as possible. Thank you!}}

[krizzu]

Thanks for your input @friederbluemle. I like this approach more - opting out instead of removing.

Also, please remove getExtOrDefault and ** getExtOrIntegerDefault** functions, as they're no longer used.

Out of curiosity - why would you open this lib as a standalone project? It makes more sense to test it directly in Android env, by running app and using the module (Unless you're writing some tests or gradle scripts).

[friederbluemle]

@krizzu - Thanks for the review. I addressed your comments, and also removed the two "getExtOrDefault" (I thought I removed them earlier, but missed it ;))
Regarding opening it stand-alone: Sometimes it can be useful to validate and compile the project in isolation, without any other projects or apps involved. It would also be possible to add unit tests that specifically target library code (and of course don't need an app project).

[krizzu]

Thanks a lot @friederbluemle @dulmandakh