Merge "Breaking out mac key signing into the context" am: feb7a62bcd am: 752cff5834 am: 294b9bdc31 am: 9a06fd4b6d am: f3ba334c7a

Original change: https://android-review.googlesource.com/c/platform/system/keymaster/+/1788496

Change-Id: Ib9767f6faf4d7fbf5c954440ec66414c76add583