Merge "ueventd: Put dm-user devices in a folder" am: e3a715a9c5 am: 9765facb89 am: f42655624b am: 6aeec14023

Original change: https://android-review.googlesource.com/c/platform/system/core/+/1461564

Change-Id: I88d96d2e441a90ef46fa61c1a6f93c49ce6af4f7