[automerge] Move device management resource retrieval calls to bg thread 2p: ae2482212d 2p: 6c81de576b

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17607256

Change-Id: I6dc0c6cdd115439f5683bf1bdc5ebd3627c88a70