Update authentication tests.

Test for multiple schemes and multiple auth headers, but
insist that one of schemes is "Basic".

Fixes CTS tests
URLConnectionTest#testAuthenticateWithCommaSeparatedAuthenticationMethods
URLConnectionTest#testAuthenticateWithMultipleAuthenticationHeaders

(cherry picked from d1b438d58c2177c9cebcc3b72df13ac9b7c46e91)

bug: 10211309

Change-Id: Icdc30a5c52cc2c8e3b65abe402732658d4308a88
1 file changed