feat(android): add "google-services.json" support

[hansemannn]

JIRA:
https://jira.appcelerator.org/browse/TIMOB-27745

Test:

1. Download the kitchensink-v2 app.
2. Build and run on Android.
3. Verify that the app builds and runs without issue.
4. Download google-services.json. (Only Axway employees can access this.)
5. Copy the google-services.json file to: ./app/platform/android
6. Build and run on Android.
7. In the log, verify that you see the following message.

[INFO]  [GRADLE] Parsing json file: /Users/<YourFolder>/kitchensink-v2/build/android/app/google-services.json

[build]

	Messages
📖	💾 Here's the generated SDK zipfile.
📖	🎉 Another contribution from our awesome community member, hansemannn! Thanks again for helping us make Titanium SDK better. 👍
📖	✊ The commits in this PR match our conventions! Feel free to Rebase and Merge this PR when ready.
📖	✅ All tests are passing Nice one! All 6659 tests are passing. (There are 698 skipped tests not included in that total)

Generated by 🚫 dangerJS against 8ff2356

[jquick-axway]

@hansemannn, can you add the below code to the top of our app.build.gradle template please? The idea is we want to automatically use the plugin if the google-services.json file exists since the plugin's main purpose is to read the file and turn it into "res" info. The below code should go just below our other apply plugin: '...' statement. Thanks!

if (file("${projectDir}/google-services.json").exists()) {
	apply plugin: 'com.google.gms.google-services'
}

Edit: Or I can finish up this PR's changes if you want.

[hansemannn]

@jquick-axway Added it!

[jquick-axway]

CR: Pass

[ssekhri]

FR Passed
Mac OS: 10.15.4
SDK: 9.1.0.v20200413130540
Appc CLI: 8.0.0
JDK: 11.0.4
Node: 10.17.0
Studio: 6.0.0.202003181504
Device: Pixel3(v10.0) emulator