Added check to know the status of any ongoing pairing status.

Use Case: Host allows incoming pairing even though outgoing pairing
is in process.

Steps:
1. Initiate bonding from Mecapp and provide pin key at Mecapp pairing
pop-up.
2. Start pairing for Logitech mouse from DUT and click on accept
pairing at mecapp pairing pop-up.
3. Give the same pin key for mecapp pairing pop-up at DUT side and
observe the behavior.

Failure: Incoming request is getting from remote and got a pop-up
for PIN request.

Root Cause: Pairing was auto accepted for remote device while
pairing was in progress with another remote device leading to
inconsistent behavior.

Fix: Rejects incoming pairing request from remote device
if already in pairing state.

Test: Tested with HID Logitech Mouse

Fixes: 35417665

Change-Id: I19a2a98e4ceb51cabaef279a2e3f8224fbed9ea1