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
Solve a possible NPE in the Documents provider

This commit follows an internal bug report to fix a NPE that would be
thrown in specific situations on specific devices. All callers should
be able to handle the returned null value but if they don't, we can
worry about that later down the line. This null value should not be
returned under normal circumstances anyway.

Change-Id: I274844bf07733643923d5729259f1d9d9cf75e54
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_frameworks_base into android-4.4