Merge "Add secure key storage api for keymaster and implement pure software secure key storage to mock secure hardware." am: f6775ab03c am: 956d41a334 am: a22b89ebc0

Original change: https://android-review.googlesource.com/c/platform/system/keymaster/+/1579865

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I236dd3a74292e03e7b7e495580be306305f11b3f