Support using T GSI key to verify GSI

Bug: 203021104
Test: vts-tradefed run vts -m vts_security_avb_test
Change-Id: I5beca50458a6d5b3ae39ee616fd1efc83997ee95
Merged-In: I5beca50458a6d5b3ae39ee616fd1efc83997ee95
(cherry picked from commit 9c89185f799a8824bb690f6a699741d7e6471ce8)
5 files changed