Verify that attestation root is a valid self-signed cert.

Bug: 38243685
Test: adb shell /data/nativetests64/VtsHalKeymasterV3_0TargetTest/VtsHalKeymasterV3_0TargetTest
Change-Id: I6b57025e4aab7d475116c51fb43ae9f31778d7c8
1 file changed