Remove react-native-gradle-plugin as a dependency from template's package.json

Summary:
We should now be able to remove the explicit `react-native-gradle-plugin` dependency
from the `template/package.json` file.

Changelog:
[Android] [Changed] - Remove `react-native-gradle-plugin` as a dependency from template's package.json

Reviewed By: motiz88

Differential Revision: D34050589

fbshipit-source-id: c8d4e4fba481af6b56723906b71411132d60aded

Author: cortinico

template/package.json

@@ -21,7 +21,6 @@
     "eslint": "^7.32.0",
     "jest": "^26.6.3",
     "metro-react-native-babel-preset": "^0.67.0",
-    "react-native-gradle-plugin": "^0.0.4",
     "react-test-renderer": "17.0.2"
   },
   "jest": {