Add debug logs to understand update start delay am: 6bec1eda3d

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/3167416

Change-Id: Id7245cfffb0976aad8fbf15c289b5a2f15eeb176
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>