Serialize the commands during Pairing process

Steps:
1. Pair and connect with HID mouse.
2. Once the settings UI shows paired and connected
3. Try to unpair the device, but UI still shows connected.

Failure: Unable to unpair HID mouse due to LMP
response timeout occurred for  remote version and remote
feature request.

Root Cause: Remote version, Remote features, Authentication
requested commands go simultaneously to the remote device
which can't handle the multiple commands at a time.

Fix: Serialize the Remote version, Remote features, Authentication
requested commands.

Test: Tested manually with apple magic mouse.
Bug: 35125883

Change-Id: I4448c291a60ee637dc5927806547e67f26571d86