Create EXTRA_INSTALL_ZIPS variable

Make needs to know about the "extra" zip files that are extracted
to the staging directories so that it can track all the installed files
correctly.

Also add a utility tool for listing the contents of relevant zips.

Bug: 337869220
Test: m droid and checked the contents of file_list.txt when adding an android_app_set locally
Change-Id: Idc5dd785b03c05f7972c66620d4e6359892b3863