[automerge] Add test for GattConnectionManager. 2p: 699f0354d7

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/Nearby/+/16947950

Bug: 204780849
Change-Id: Ide3caf14d2a53c35ce280618e1d7803ce6ce1b42
tree: 29b955876a30e1e82458bc3c36eb04cd8bcdc0d6
  1. nearby/