Merge "Add an isCheckpointing() binder call for adb remount." am: b50480bb96 am: 60e41b7084 am: 026ae1a9ac

Original change: https://android-review.googlesource.com/c/platform/system/vold/+/1330854

Change-Id: I4739db7174b247defd39291aad8915dfefc1d1cc