Gallery2: DA translation

Change-Id: Ic3e5d0f538ae94d11a9e9540f485c8dcd11ac008
Merge "Gallery2: DA translation" into cm-10.2
Gallery2: fix HDR crashes && fix exposure from being set.

* HDR transcoding is done on a different thread. got rid of the
stall in the transcooding step and possibliy fix race conditions.
* lock out the exposure step from being set, also fix an issue
of setting is being set by a method that is called on idle.

Change-Id: I9558558777a11cc8f6b633e397c809aa6993ceaf
merge changes from CyanogenMod 10.2 into local branch