Bring back the status bar activity indicators for mobile data and wifi

Google were nice enough to create xxhdpi drawables for us before removing them.

Reverts "Remove signal/wifi activity indicator icon overlays."

This reverts commit fcc901c10bffdfb9c6b31e676dec36b47d949979.

Change-Id: I7aa85f7c8442c45d17e42cac7823dfe93e3f24c1
Avoid layout passes when updating data activity indicators.

ImageView can optimize out layout passes if old and new drawable have
equal sizes. Take advantage of that by displaying a transparent drawable
with the same size as the in/out drawables when there's no activity
instead of clearing out the drawable in that case.

Needs https://gerrit.slimroms.net/3678

Change-Id: Iaaa556ffab3ed4be1da8016ed40d0a9c2efcde01
Fixed retrieving non-initialized wallpaper information

When an attempt is made to retrieve wallpaper information such
as getWidthHint during user switching, the wallpaper may be
uninitialized and therefore throw NullPointerException.

Resolved by initializing wallpaper for current active user
if not yet initialized or returning null if applicable.

Change-Id: I1d3931379cbf4ea82cd25bc813898bbe4fb65a67
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
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
Merge branch 'kitkat' of http://github.com/HyperionROM/frameworks_base into kitkat