Fix to double deletion of StreamingZipInflater object.

Race condition can cause double deletion during stability runs
of StreamingZipInflater object. This is possible due to delete
of mZipInflater occuring at two seperate locations in owning
_CompressedAsset object. Fixed by securing object is set to
null on member reference before calling delete. Also secured
that all deleted objects in StreamingZipInflater are set to
null after delete.

Change-Id: I87ef0fa78835ea05c524b3d818c8e6aa2aee1fe4
Prevent MediaScanner infinite loop with invalid path

including double slash  "/storage/sdcard0/xx//xxx/xxxx"

Change-Id: I112a70c88b5ec662482b79c3151310b9b9b52e40
Text size for empty view shall be styled according to theme

In activity_list.xml the empty TextView has set a
textAppearance which allows the theme to set the font size.
However, for preference_list_fragment.xml the textAppearance
is missing but should follow the same style as
activity_list.xml

The missing textAppearance makes the empty text in
Settings->Wifi and Settings->Bluetooth look small if
no networks are found.

Change-Id: I9320b37cfeec0d9505d73650696eaf534fc4a321