RSA OAEP MGF1 digest VTS relaxed for keymint < V3

Since there were no VTS test to strictly check RSA_OAEP_MGF_DIGEST,
there are released devices with Keymint which do not include this tag in
key characteristics, hence these test fails on such Keymint and UDC
Android framework.

Hence version check is added before asserting MGF digest checks.

Bug: 297306437
Test: atest VtsAidlKeyMintTargetTest
Change-Id: I43054f8dbbd46de53deef5e6771c736e770280e0