Add mention of ReactActivity in the edgeToEdgeEnabled comment (#145)

Author: zoontek

template/android/gradle.properties

@@ -40,4 +40,5 @@ hermesEnabled=true
 
 # Use this property to enable edge-to-edge display support.
 # This allows your app to draw behind system bars for an immersive UI.
+# Note: Only works with ReactActivity and should not be used with custom Activity.
 edgeToEdgeEnabled=false