Merge of https://widevine-internal-review.git.corp.google.com/c/cdm/+/208111 Signature is generated from public_key1, so we should use key_type1 for signature verification. Test: opk_ta_p40 Bug: 355011375 Change-Id: If532f3814c7a4b7899d574fc09d3d09b9bb18976