Merge "libsnapshot: Add diagnostics for DM_DEV_REMOVE failures." am: 055f802086 am: 547a61c8f4 am: 697c5e72e1

Original change: https://android-review.googlesource.com/c/platform/system/core/+/1668591

Change-Id: Icec6fcc3c8f889e2dec7c5ae0a536b0c773dbc65