Merge "ApexSignatureVerificationTest for vendor apexes" am: 82a689cca1 am: e62e4fec23 am: 9eafee9d07

Original change: https://android-review.googlesource.com/c/platform/cts/+/1479637

Change-Id: I60dd01c876c5b08e33a1777581975b3dffb24b1c