Merge "Add an isCheckpointing() binder call for adb remount." into rvc-dev am: f87198e025 am: 9f054be265

Original change: https://googleplex-android-review.googlesource.com/c/platform/system/vold/+/11917729

Change-Id: I6d255fe56cc04895887417d2eced22cb0f8ea0e5