[automerger skipped] Keystore 2.0: Teach keystore to decrypt generic blobs. am: d647b4a5b3 -s ours

am skip reason: Merged-In Id8561d3f98d53182709d9f4feeeecda3b1535077 with SHA-1 f84d0b0520 is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/system/security/+/16909355

Change-Id: I907ba147c7a8417363c78c9a969c3a366fb514ea