Merge "Add AuthMgr README" into main am: 91a7beb65d am: f3bc8704ef

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/3492770

Change-Id: Ib4cf172073596e3f9845d1b166627cd7b3f1875b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>