Record contents of EXTRA_INSTALL_ZIPS files in file_list.txt

The partitions will not include anything that's not in file_list.txt.

Zip files in EXTRA_INSTALL_ZIPS are extracted into the staging
directories when other files are installed. Their contents need to
be added to the file_list.txt so that their extracted files are not
ignored.

EXTRA_INSTALL_ZIPS is only used by android_app_set, which is only used
by partners, so this bug went unnoticed for a long time.

Bug: 337869220
Test: m droid and checked the contents of file_list.txt when adding an android_app_set locally
Change-Id: Ifa2f7168dbeedbb2308a481c0c78f28e874b0aef