Update installation-android.md

docs/installation-android.md

 
 		protected List<ReactPackage> getPackages() {
 			// Add additional packages you require here
+			// No need to add RnnPackage and MainReactPackage
 			return Arrays.<ReactPackage>asList(
 				// eg. new VectorIconsPackage()
 			);
 
 		@Override
 		public List<ReactPackage> createAdditionalReactPackages() {
-			return this.getPackages();
+			return getPackages();
 		}
-		// No need to add RnnPackage and MainReactPackage
-		// Simply return null if you do not have additional packages:
-		// return null;
 	}
 	```