Expanded Desktop : Fix Left handed navbar during landscape mode

from http://review.cyanogenmod.org/#/c/57454
when you enable expanded desktop and left handed navbar.
you need to swipe from right edge to show navbar.
but this patch will change to swipe from left edge to show navbar.
Video avalible at http://youtu.be/rUy14LQj9iE

Patchset2 : change tab to whitespace
Patchset3 : remove \r after @override in PhoneWindowManager.java
Patchset4 : Update commit message
Patchset5 : Address code formating comments
Patchset6 : Whitespace

Change-Id: I65a15c6f5e662e429a818484de6b71e81c7ae713
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
Release locked buffer when it fails to acquire graphics buffer

The JNI buffer in ImageReader_imageSetup is not released when
it fails to acquire graphics buffer. After all JNI buffers are
exhausted, ACQUIRE_MAX_IMAGES will be returned and leads to
error. The JNI buffer should be released when it fails to acquire
graphics buffer.

Change-Id: I3319a58ac44e36c8593b404672a685c4b589a735