Set foreground priority for shutdown receivers.

The broadcast of ACTION_SHUTDOWN has a timeout of 10 seconds. To
reduce the risk of hitting the timeout and speeding up the
shutdown sequence in ShutdownThread we set the priority of the
BroadcastReceivers to FLAG_RECEIVER_FOREGROUND.

We have seen that this change reduces the shutdown time when
the system is under heavy load.

Change-Id: I22cbf6af8cf6fc4bdefaa1c3da8a7eed7e7b7674
Merge "Set foreground priority for shutdown receivers." into jb-mr1
Merge remote-tracking branch 'aokp/jb-mr1' into jb-mr1

* changes:
  Set foreground priority for shutdown receivers.
  Ensure install-during-restore is like install-then-restore
  Validate restored file paths against their nominal domain
  libdrm: fix bad strncpy / snprintf calls
  Add a delimiter between scheme and host
  Lockscreen : Reference correct layout
  Avoid adding FORWARD_LOCK flag to an updated system app
  Fix deadlock of WebViewCoreThread
  QuickSettings: FavContact & UserTile: Open full contact page