[automerger skipped] Update Security String to 2021-10-01 am: 6ccb50dd am: 3644c700 -s ours am: c3aea2a2 -s ours am: 71d33ddc -s ours

am skip reason: Merged-In I4a0cd58b18214b77302ae7ed81c189f4549dc41d with SHA-1 91cbb676 is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/build/+/15564069

Change-Id: I13cf2ce6159a566bcba37b4649082c8717147c2e