frameworks: add persistent notification when USB OTG is connected

Tapping the notification will take the user into Storage settings, and
highlight the 'Unmount' option.

Change-Id: I650f3874a8295b2b8ffdaef78aff4b68e9cd574e
Signed-off-by: Roman Birg <roman@cyngn.com>

Conflicts:
	core/res/res/values/symbols.xml
Themes: Fix native crash in libandroidfw

If a missing attribute needs to be added in somewhere in the middle
of the bag, a segfault would occur because we change curEntry to a
value that is beyond the set's allocated space.  This patch stores
curEntry in prevEntry before changing it's value and memmove uses
prevEntry to index the set.

Change-Id: Ie70f2ad465097c3acf76caa729999c424fb01ee2