Merge "Add README." into main am: 06cc64d820 am: 21d5a0039c

Original change: https://android-review.googlesource.com/c/platform/development/+/2843615

Change-Id: I960ad0fa5af9539cd2bb24760cbcadb115aea4a8
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>