Add missing \n on helloworld gradle.properties

Author: cortinico

private/helloworld/android/gradle.properties

@@ -15,4 +15,4 @@ edgeToEdgeEnabled=false
 # Opt out of built-in kotlin and new DSL behavior that ships with AGP 9.
 # Starting from AGP 10.x these opt outs will be removed.
 android.builtInKotlin=false
-android.newDsl=false
+android.newDsl=false