Updated the Android build files so a new project builds on creation

[patm1987]

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The Android Gradle Plugin has been updated from 3.4.0 to 7.2.1 -- https://developer.android.com/studio/releases/gradle-plugin#7-2-0 jcenter() has been updated to mavenCentral() -- https://developer.android.com/studio/build/jcenter-migration The gradle wrapper has been upgraded to 7.3.3 (required for the Android Gradle Plugin) -- https://developer.android.com/studio/releases/gradle-plugin#updating-gradle The default ABI has been changed from armeabi-v7a to arm64-v8a since it's mandatory for new games -- https://developer.android.com/games/optimize/64-bit