Settings: Lockscreen Targets Icon Revamp

Adjust the size of custom app icons and resize and round the corners
of gallery icons for a more uniform look.
Merge remote-tracking branch 'aosp/jb-mr1.1-release' into jb-ras-mr1.1
use darker black for appwidget_bg_holo/appwidget_item_bg_normal
Merge remote-tracking branch 'upstream/jb-ras-mr1.1' into jb-ras-mr1