Prevent audio players starting on startup.

Previously, (at least) Apollo was started on startup (in that it
appeared in the notification bar) because it listens to the AUDIO_BECOMING_NOISY
intent to silence itself in that case. This intent is broadcast by
AudioService when there's a user switch to silence any potential audio
players for the old user. As the system also sends around a
USER_SWITCHED intent on startup, this led to the aforementioned player
startup.
As the intent of AudioService was to act on a user backgrounding anyway,
send out AUDIO_BECOMING_NOISY as reaction to a USER_BACKGROUND intent
instead of the USER_SWITCHED intent.

Change-Id: Iba35844a1274c9dd195f104068304e6a7ffa809e
Framework: Fix multi-user support in AudioService

Change-Id: Iddeeeac0734a237103e238bcdaa1e85806a64e4f
SystemUI: Remove the dark pixel artifacts from the back arrow drawable

The arrow had some mostly transparent pixels that made it look
kind of like the device had defective pixels. Found by Cyril Mottier.

Change-Id: Ia78453868ebe7e3291d01c96b9beafc78ea3cdcc

Conflicts:

	packages/SystemUI/res/drawable-xhdpi/ic_sysbar_back_land.png
PackageManager: Restrict system packages to protected storage

Don't allow packages signed with the platform key to be
installed into user (or app) controlled storage

Change-Id: I7390b3bdf5289411f7a335c69635bed9f74bbfb3
SystemUI: HSPA+ Support

Add the ability to recognize HSPA+ by creating a separate case for HSPAP and
include new H+ icons.

Signed-off-by: Bajee11 <bajee11@gmail.com>
Change-Id: I889a28e4b4cb49862b291641df5a00388db87551