Merge "Add instructions to generate java keystore" into main am: 31e9d3d1 am: 19dae885

Original change: https://android-review.googlesource.com/c/platform/build/+/3104279



Change-Id: I3c6a4a36fa8b0d32ba0b6df8299517c6ecc3029e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>