systemui: Fix crash on theme change

 * Avoid NPE on theme change on devices without a navigation bar.

Change-Id: I29321e7747e7aa87f4539913b5a071f6e7d6a72d
Sensor: Enable the motion accelerometer for screen orientation change

The screen orientation can be detected by the motion accelerometer
instead of generic accelerometer to save power.
Change-Id: Iaeb3e5958d2ef7cc33080d7091ed8a5462695c67
A background started service is removed from mStartingBackground when timeout.
Fix is to make sure mStartingBackground is updated to remove one.

Change-Id: I0e42beb550d33e6e400349b85bbb89848e18d520
Fix, MountService now only sends one onShutDownComplete

The event onShutDownComplete are sent only when all
volumes are shutdown. (Not one for every volume.)

Change-Id: I6af521ee8285ca581efac7d3c5f013dfbff3ee30
Finish fixing Zygote descriptor leakage problem

In order to prevent Zygote descriptors from leaking into the child
environment, they should be closed by the forked-off child process
before the child switches to the application UID.  These changes close
the descriptors via dup2(), substituting a descriptor open to
/dev/null in their place; this allows the Zygote Java code to close
the FileDescriptor objects cleanly.

This is a multi-project change: dalvik, art, libcore, frameworks/base,
and external/sepolicy are affected.  The CLs need to be approved
together, lest the build break or the software fail to boot.

Round 2: indent change

Bug: 12114500
Change-Id: I090402136a8a8b7d6aad6eb153026e85d7cf6ad3