Merge "Rewrite how to generate apexkeys.txt" into main am: aea4c9d4

Original change: https://android-review.googlesource.com/c/platform/build/+/2809200



Change-Id: I7b4f5bf34b61effe84d8c90e62d23aac785b0b68
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>