webview: Adjust examples in appendAuth... tests to specific path.
webview: Adjust examples in appendAuth... tests to specific path.

This unusual form of authentication is only accepted by the server
under one specific URL path, so adjust the tests to reflect that.

vishwesh3/zulip-mobile,vishwesh3/zulip-mobile,vishwesh3/zulip-mobile,vishwesh3/zulip-mobile