Add oatdump support for app images

Example usage on host:
oatdumpd --app-oat=art/plus32.odex --app-image=art/plus32.art
--image=art/oats/system@framework@boot.art --instruction-set=arm

TODO: Add to oatdump test.

Bug: 27408512
Bug: 22858531

Change-Id: I320db8b76c780c6eadabcb45ce88f45950741484