Added AccessPoint.matches(AccessPoint) method to match AP objects

Previously there was no single method to match two AccessPoint objects
that represent the same method. This provides a clear method to match
AccessPoints of the same network (especially Passpoint networks).

Test: atest AccessPointTest
Bug: 130373102

Change-Id: I14eae0e331a5253f4be52c2835b5629172ca23ba