breaking: Bump android gradle plugin to 3.6.0

[breautek]

Platforms affected

Android

Motivation and Context

Upgrades android gradle plugin to 3.6.0.

afaik there are no issues that are dependant on this change, but this is usually considered a breaking change, so it would be great to be included in the 9.0.0 release.

Description

Updated the framework and the two android test projects version pins.

Testing

ran npm test

Checklist

• I've run the tests to see all new and existing tests pass
• I added automated test coverage as appropriate for this change
• Commit is prefixed with (platform) if this change only applies to one platform (e.g. (android))
• If this Pull Request resolves an issue, I linked to the issue in the text above (and used the correct keyword to close issues using keywords)
• I've updated the documentation if necessary

[timbru31]

Release Notes are over here: https://developer.android.com/studio/releases/gradle-plugin#3-6-0

[erisu]

3.6.3 I believe is actually the latest release from April.

https://mvnrepository.com/artifact/com.android.tools.build/gradle/3.6.3

[breautek]

I used https://developer.android.com/studio/releases/gradle-plugin to determine the latest, they don't mention 3.6.3 O.o

3.6.x changes shouldn't be breaking anyway, so if we need it should be easy to update at anytime.