Add merge_ota to otatools am: 792dfa53

Original change: https://googleplex-android-review.googlesource.com/c/platform/build/+/23371285



Change-Id: Id4430685f1c96f216d029c20621d08317aba9e58
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>