Revert "ContentProvider: Avoid duplicate initialization of AsyncTask"

This change leads to soft reboots.
To reproduce:
  *) Take a screenshot
  *) Share it a few times
  *) The chooser dialog should appear but instead the system dies

E/AndroidRuntime( 4993): *** FATAL EXCEPTION IN SYSTEM PROCESS: PowerManagerService
E/AndroidRuntime( 4993): android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
E/AndroidRuntime( 4993): 	at android.view.ViewRootImpl.checkThread(ViewRootImpl.java:6027)
E/AndroidRuntime( 4993): 	at android.view.ViewRootImpl.requestLayout(ViewRootImpl.java:820)
E/AndroidRuntime( 4993): 	at android.view.View.requestLayout(View.java:16455)
E/AndroidRuntime( 4993): 	at android.view.View.requestLayout(View.java:16455)
E/AndroidRuntime( 4993): 	at android.view.View.requestLayout(View.java:16455)
E/AndroidRuntime( 4993): 	at android.view.View.requestLayout(View.java:16455)
E/AndroidRuntime( 4993): 	at android.view.View.requestLayout(View.java:16455)
E/AndroidRuntime( 4993): 	at android.view.View.requestLayout(View.java:16455)
E/AndroidRuntime( 4993): 	at android.view.View.requestLayout(View.java:16455)
E/AndroidRuntime( 4993): 	at android.view.View.requestLayout(View.java:16455)
E/AndroidRuntime( 4993): 	at android.view.View.requestLayout(View.java:16455)
E/AndroidRuntime( 4993): 	at android.widget.AbsListView.requestLayout(AbsListView.java:1972)
E/AndroidRuntime( 4993): 	at android.widget.AdapterView$AdapterDataSetObserver.onChanged(AdapterView.java:814)
E/AndroidRuntime( 4993): 	at android.widget.AbsListView$AdapterDataSetObserver.onChanged(AbsListView.java:6482)
E/AndroidRuntime( 4993): 	at android.database.DataSetObservable.notifyChanged(DataSetObservable.java:37)
E/AndroidRuntime( 4993): 	at android.widget.BaseAdapter.notifyDataSetChanged(BaseAdapter.java:50)
E/AndroidRuntime( 4993): 	at com.android.internal.app.ResolverActivity$LoadIconTask.onPostExecute(ResolverActivity.java:756)
E/AndroidRuntime( 4993): 	at com.android.internal.app.ResolverActivity$LoadIconTask.onPostExecute(ResolverActivity.java:744)
E/AndroidRuntime( 4993): 	at android.os.AsyncTask.finish(AsyncTask.java:632)
E/AndroidRuntime( 4993): 	at android.os.AsyncTask.access$600(AsyncTask.java:177)
E/AndroidRuntime( 4993): 	at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:645)
E/AndroidRuntime( 4993): 	at android.os.Handler.dispatchMessage(Handler.java:102)
E/AndroidRuntime( 4993): 	at android.os.Looper.loop(Looper.java:136)
E/AndroidRuntime( 4993): 	at android.os.HandlerThread.run(HandlerThread.java:61)

This reverts commit d22a5b851abf2a06097db51368edfda7616fc34c.

Change-Id: Ibe9c1192ec73eb46e3359da991201f6088e3a78e
Allow granting permissions based on signature in <allow-permission/>

This patch allows us to either specify a sharedUserId or a package
signature to use when granting the specific permission.

Change-Id: I8aed78d40316e0e94ac1bfefc7c4a3016a2a9a6b