Merge "docs: Clarify when certificate is self-signed" into main am: 69bbd1c84f am: 76ee840072 am: a14b6b8858

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2779947

Change-Id: Ia21b574776ec7475e6c54f66283e56706aa52704
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>