Merge "EncryptInPlace: ensure that backup superblocks get encrypted" am: 213dbe30a1 am: 5acfc3e8d5 am: d1a7e750e2

Original change: https://android-review.googlesource.com/c/platform/system/vold/+/1385029

Change-Id: Ib38c9b7459b1dcd4c8b00334bcf4375d81d590fe