Reset the pairing state on pairing failure

Use case: Test the paring scenario with remote device with security mode 3.

STR:
1. Create a connection from Remove dev with Security Mode-3 to DUT.
2. Enter pin key in remote, when pin key pop-up comes in DUT, reject the same.
3. Try to create connection from DUT to Remote dev-2, within 30 seconds.

Failure: Create connection not sent from DUT to remote, even though
there was no pairing taking place

Root cause: As the pairing state is not reset properly it disturbs
the next pairing process.

Reproducible using MecApp test application.

Fix: Reset the pairing state to idle in case stored paring
device matches with the device for which the pairing
failure happened.

Bug: 21896912
Change-Id: I0a9e143a44bb2ae7e296d7d76c1323e517f9cc42