Android : Gradle buildTypes + flavors - providers and GCM

====PROBLEM====

I am trying to allow the installation of both debug and release versions on one device. My app is made of few modules and I have 3 flavors. All of these modules have different packages in their manifest. The way I'm dealing with my ContentProviders is:

 <provider
        android:name="com.myapp.testapp.modules.mailboxes.MailboxesProvider"
        android:authorities="${applicationId}.provider.MailboxesProvider"
        android:exported="false"
        android:multiprocess="true" >
 </provider>

private static final String AUTHORITY = BuildConfig.APPLICATION_ID + ".provider.MailboxesProvider";

And it looks like its ok but when I am trying to install second one(debug) I get error [INSTALL_FAILED_CONFLICTING_PROVIDER], also whenever I install the first one(release) there is info about problem with GCM persmissions even tho I am changing its package accordingly:

<permission android:protectionLevel="signature"
    android:name="${applicationId}.permission.C2D_MESSAGE" />
<uses-permission android:name="${applicationId}.permission.C2D_MESSAGE"/>

====QUESTION====

Is applicationId enough to deal with all different packages? Why I'm getting GCM errors even tho I change the package info?