When building images set the mount point (data,cache,system) as the
filesystem label on the generated image. This is required for the
Android Emulator.
IMPORTANT: This depends on the following patch to system/extras/:
https://android-review.googlesource.com/#/c/120047/
which has already been submitted to AOSP and merged into the
internal tree.
Change-Id: Iaeb45462570c26d37980f1cc5d8a1b929e476c89
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>