Remove usage of WebView.setCertificate

This method will be a no-op in the Chromium powered webview.  It looks
like it may have been exposed only as a convenience for testing.  This
change updates the tests to no longer use or rely on the method.

Bug: 5012961
Change-Id: I1a88464bd1acc46e72cfe82f6e3256a7482122cf
1 file changed