Re-order skip checks for attestation tests

Put the test arm that just involves checking a property
first, so that tests which involve a round trip to the Package
Manager are only executed when they're needed.

Test: VtsAidlKeyMintTargetTest
Bug: 271026714
Change-Id: I4caad6243a3b9d511a32717fd95f58864b857eeb
1 file changed