KeyMint VTS: better early boot key tests

Add a check that the TAG_EARLY_BOOT_ONLY is included in the returned key
characteristics.

Bug: 188672564
Test: VtsAidlKeyMintTargetTest
Merged-In: I200c61f34888c720c47f6289d79cd21d78436b58
Change-Id: I200c61f34888c720c47f6289d79cd21d78436b58
Ignore-AOSP-First: already merged in aosp/master
2 files changed