filter non-gsi images from gsi package

because the lunch same target (e.g., aosp_arm64) can be used
for GSI (general system image) and other full systems, such
targets can include files that are not related to GSI. Thus,
those unrelated files are filtered.

Test: run
Bug: 80004983
Change-Id: I20b69280811d4dc0ea635871943c310b63382e18
Fix: 80004983