Fixing build dependency in build.gradle.
Fixing build dependency in build.gradle.

Change-Id: Iaee729d0e755c570b122d4f70e67d272605999dc

claywilkinson/play-games-plugin-for-unity,claywilkinson/play-games-plugin-for-unity,claywilkinson/play-games-plugin-for-unity,claywilkinson/play-games-plugin-for-unity