Add single crunch command to aapt. do not merge.
Previously the crunch command would work on a full res folder
and output a full res folder (with only the drawables). This
was only used in the SDK.
The incremental logic is moved to the SDK build system so we
change the crunch command (or rather add a new one) to only
crunch a single file.
(cherry picked from commit b1f6ad82dd8d1702617a757a88430604b3131fac)
Change-Id: Ifa0dceed93708658f950322f36c13b6ebe7ab0f3
42fb3abd4b