Fix Android Gradle "compile" deprecation warning

[AndrewJack]

Since RN 0.57 the android build tools were updated from 2.3.3 to v3.1 (https://github.com/facebook/react-native/commit/6eac2d4)

When using compile in the build.gradle file it generates the following error: WARNING: Configuration 'compile' is obsolete and has been replaced with 'implementation' and 'api'. It will be removed at the end of 2018. For more information see: http://d.android.com/r/tools/update-dependency-configurations.html

I have changed the config from provided to api, the same as most react native libraries:

• https://github.com/react-native-community/react-native-device-info/pull/520
• https://github.com/react-native-community/react-native-netinfo/blob/master/android/build.gradle#L41
• https://github.com/react-native-community/react-native-webview/blob/master/android/build.gradle#L127

[jordanbyron]

Thanks for the update @AndrewJack!