Add forcing flag to failing DataSaver ChromeDriver test

The server recently disabled ServerLoFi by default, so this adds the
forcing flag needed.

See bug for more details.

Bug: 953406
Change-Id: I107aad70acff14fd7c27c58b8bae0601d7fa26df
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1570541
Reviewed-by: rajendrant <rajendrant@chromium.org>
Commit-Queue: Robert Ogden <robertogden@chromium.org>
Cr-Commit-Position: refs/heads/master@{#651463}
1 file changed