Fix flakyness in PairingTest

When service discovery is requested, RemoteDevices always sends an empty
ACTION_UUID intent after 6 seconds. Other intents may come before or
after this intent. So there is no fix order for these events.

Test: atest BumbleBluetoothTests:PairingTest
Bug: 342946039
Flag: EXEMPT, test change
Change-Id: I0dfab96211a44e27ef6071b82df54cdaf076ae4c