Initialized unitialized variables. am: 3e881aa30f

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/2209803

Change-Id: Ic7004df35c4843e1e99b065635bfccb05f13da06
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>