Remove direct connection after notifying the connection up

After notifying the connection up, remove direct connection related with
this device to make sure no client is directly connecting the device in
connection_manager.

Bug: 138819537
Test: 1. Repair BLE device 2. Reconnect BLE deivce
3. reboot DUT, make sure Hearing Aid can be connected.

Change-Id: I30ff7c47445ec2a3dbd9702ca79873063210e6df