L2CAP error codes added to handle L2CAP CoC behviour effect RFCOMM handling of L2CAP events.

Reverting behavioural change introduced in aosp/2420440. RFCOMM checks L2CAP_CONN_INTERNAL_MASK to make sure no L2CAP connection error was found other than what was expected.
However, all errors in classic connection were reduced to other errors in the underlying layers. Introducing the new error codes and sending the correct code hence caused a behavioural change.

This fix should address the behavioural change introduced in classic connection on l2cap connection failure and keep everything else intact.

Bug: 278915729
Test: Needs to be mannually tested by using Samsung Wear App with Galaxy buds paired. Refer the bug for repro steps.
Change-Id: I9c608abb464f519aaaa511729f7cffd01bcfdca3