Fix compat for Play Services v15+ on Android

As per issues #238 & #247, this release fixes the build issue when using Play Services v15+.

This should allow for better compat with other React Native modules using a Play Services version >=15.

The module automatically uses the highest version, but if you want to use a specific version, this can be done through the googlePlayServicesVersion project build property in Gradle. You can specify it in <your-RN-app>/android/build.gradle:

buildscript {
    ext {
        googlePlayServicesVersion = "16.0.3"
    }
	// ... rest of gradle buildscript
}

See example file.

This change should be backwards compatible with older Play Services versions as well (at least >= 10).