Update CredentialStoreSaslAuthenticationTest

Currently, the CredentialStoreSaslAuthenticationTest test class only contains a test for the successful authentication case. Notice that the existing test case makes use of a wildfly-credential-sasl-config.xml file to specify the client credentials to use when establishing the connection to the server. This file is passed in when creating the SaslClient. The configuration to be used by the server itself is specified using the SaslServer class.

This task is to add a new test case to this class for the failed authentication case, i.e., the case where the wrong password is specified by the client.