Call SkipInstall() on all test_packages

The test package should never be installed. It's probably being
installed on some devices because it appears on the command line for
disting, and there's non-hermeticity bugs with installed files.

Bug: 402745063
Test: abtd
Change-Id: I9d2b1671fbef0ed78a4b4bafc6e858dade4bfac4