ASACORE-1020 About Feature

If RemoveMatch returns org.freedesktop.DBus.Error.MatchRuleNotFound
then ER_BUS_MATCH_RULE_NOT_FOUND status is returned not
ER_BUS_MESSAGE_BUS_ERROR.

Unit test verifying that calling CancelWhoImplements with bad interface
name returns ER_BUS_MATCH_RULE_NOT_FOUND.

Change-Id: I2342d11a827812762cb9c7c0609e7aee3fd47444
Signed-off-by: George Nash <georgen@qce.qualcomm.com>