Make sure to always update pending intent.

Otherwise, when having a successful download first and a failure
afterwards, the extras won't be properly cleared.

Change-Id: I2df918af7eb330898f5801aa741920a782ea6779
CMUpdater's permissions now require it to be privileged

for REBOOT and WRITE_CACHE

Change-Id: Ife5d1ee82f40a87b9632bf932d055ac291c65ce0
Cleanup: Remove shared pref settings instead of overwriting them with
dummy values.

Change-Id: I28dd86911ba86b6c787a5f6313fffed63f773cee