l2cap: Add proper handling of L2CAP Reject command

This patch fixes scenario when Android is wating for
Credit Based Connection Response, but remote side does not undestand the
command.

It also fix handling Credit Based Connection Response Negative

Bug: 237399985
Test: atest BluetoothInstrumentationTests
Test: L2CAP/ECFC/BV-01
Tag: #feature
Change-Id: I02d63ea405cb7b6e6bc6d7a30e810be2c0a47805