Fix AttestKeyTest failures in KeyMint VTS

Skip attestation key tests if the feature
FEATURE_KEYSTORE_APP_ATTEST_KEY is disabled on device,
as done in KeyMint CTS.

Bug: 244460948
Bug: 265740739

Test: VtsAidlKeyMintTargetTest
Change-Id: I8199e5c7570b10b71f127c7439b889c0b3327865
1 file changed