Unconditionally save checkpoints when force = true am: 3265b317b3 am: bfb78c318e

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/1532419

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ie74ec7e1786fc01aebc65ab5bdb1c785344bba5f