disable new_window_null.tentative.html on android under the correct path

Differential Revision: https://phabricator.services.mozilla.com/D35813

bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1559494
gecko-commit: ef772f4c6eeccdfaaf2f1fde1a71119a5547b951
gecko-integration-branch: autoland
gecko-reviewers: jdm

Author: AndreeaPavel