Bluetooth: Make pairing notification cancellable

Add actions to the pairing service notification so the user can dismiss
the pairing request if they want to.

Add some more information to logs when the user takes an action.

Reformat the file to match android style.

Test: pair from a remote device, dismiss using the new actions
Bug: 36036358
Change-Id: Ie110044bd4caf465f454452737000f01e7430925