Bug 881137 - Update the image files as 1.5 times bigger images.
Bug 893310 - hdpi/xhdpi replacing @1.5x images assets for Gallery app
Merge pull request #10957 from cctuan/master-gallery

Bug 893310 - hdpi/xhdpi replacing @1.5x images assets for Gallery app, r=timdream
Merge pull request #10805 from evanxd/bug-881137-images

Bug 881137 - hdpi/xhdpi resolution assets and layout for Calendar app