Make sure the base_image is used in build_app

At least make sure that "shift" is called
If we don't do this then it can have unintended side effects
when calling other bash scripts as $1 is still set.

Change-Id: I9543f124a47f0c878d7a4d15a3b942ea83e15333
Merge "Make sure the base_image is used in build_app"