Do not show Home behind full screen activity

When ensureActivitiesVisibleLocked goes through foreground activity
stack and reaches non-fullscreen activity, it sets showHomeBehindStack
variable to true.

If there is a fullscreen activity behind, showHomeBehindStack remains
unchanged, which causes Home application to be displayed anyway.
In this case user will see a fullscreen activity and Home activity
simultaneously.

To fix the issue we set showHomeBehindStack to false when we reach
fullscreen activity in the activity stack.

This was made visible by the following commit:
446ef1de8d373c1b017df8d19ebf9a47811fb402

Change-Id: I535c1283a4e26f5cf606375b837d4b7195324af0
Prevent Lockscreen album art from activating FLAG_KEEP_SCREEN_ON

This is a small fix to the showWallpaper method, in which a power
consumption problem has been introduced. This showWallpaper method
toggles the window flag FLAG_SHOW_WALLPAPER, when album art is being
shown in Lockscreen. It is important to set pixel format to
PixelFormat.OPAQUE if flag FLAG_SHOW_WALLPAPER is not being set.

If not, an application that uses window flag FLAG_KEEP_SCREEN_ON
will prevent the keyguard from going to sleep and drain battery.

Change-Id: I1808be28047977ae5ac4dd1168ea25cac8a55a78

Conflicts:
	packages/Keyguard/src/com/android/keyguard/KeyguardViewManager.java
Hang off call by power button while screen is on

Enable power button end call and screen is off.  User use power button
to turn on screen will end call.  Should turn on screen and not end call

Change-Id: Idf34f7724dbf1796205332c5c7ef663102f8a30c
Signed-off-by: shower <shower929@gmail.com>
Parallel shutdown

Decrease shutdown time by doing some shutdown tasks in parallel.

There are two threads executing during the shut down: the ShutdownThread
and a separate thread for the radio shutdown. However, the execution is
done in serial, as the ShutdownThread immediately joins on the radio
thread.

This commit will move the shutdown of the radio to the beginning of
shutdown and execute it in parallel to the shutdown of the rest of the
system.

The flow of the two threads during shutdown is now:

Radio Thread
  * Start shutdown of the radio
  * Wait for radio off or time out
  * Notify that the radio is done
ShutdownThread
  * Broadcast ACTION_SHUTDOWN as a parallel broadcast. (The receivers
    will get as much time to handle onReceive as it takes execute the
    rest of the tasks in the shut down flow. If they are not done in
    that time, we don't care.)
  * Shutdown ActivityManager
  * Shutdown MountService
  * Wait for MountService and radio to notify done
  * Vibrate
  * Low level shutdown

Change-Id: Ifdd8a9c75337fd9d00148a0d2b9917e10fa60634

Conflicts:
	services/java/com/android/server/power/ShutdownThread.java