[automerge] [Offload] Fix race condition in DiscoveryProviderManager 2p: 69551222e9

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/20592218

Change-Id: Ibb461c07a02c6e6d634020f3ed1d700a28ac5a36
Ignore-AOSP-First: nearby_not_in_aosp_yet