In my code there is an inner class that extends BroadcastReceiver.
And I have added the following line to the AndroidManifest.xml:
you dont need to use $... If you get warning for a class which is not actually an inner class, it's because you are using uppercase characters in your package name, which is not conventional.
I tried also to change only the first letter of the package name to be lower case, the warning and error disappeared.