Merge "docs: Clarify when certificate is self-signed" into main am: 69bbd1c84f am: 76ee840072 am: a14b6b8858 am: 8aa1722130

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

Change-Id: I974dcf5a9c78343be94549a7913004eed16e2a14
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>