KeyMint VTS: local asymmetric verification

Change verification of ECDSA and RSA signatures so it happens locally
in the test, rather than by invoking a VERIFY operation against KeyMint.

Bug: 188385353
Test: VtsAidlKeyMintTargetTest
Merged-In: I0efc30f3c96cd70ac636d34718eff53cc23f1480
Change-Id: I0efc30f3c96cd70ac636d34718eff53cc23f1480
3 files changed