[Mfill Android] Rewrite test to enable update of support library

The matcher used to select the image of the tab isn't working with the
support library in version 28. This is probably due to an internal
change of how descriptions are set inside Tabs.

This CL removes the reliance of espresso matchers and relies on the
public interface of TabLayout instead.

Bug: 956280
Change-Id: Ied5c456fb7c7b433d7a897b7d9f043c1b5c1ee5c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1582504
Reviewed-by: Jan Wilken Dörrie <jdoerrie@chromium.org>
Commit-Queue: Friedrich [CET] <fhorschig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#653955}
1 file changed