[autotest] opt-in to test retries in desktopui_WebRTC test

Due to the recent change in test retry behavior, this restores test
retries to desktopui_WebRTC. For now, this test will retry after type of
failure.

BUG=None
TEST=None

Change-Id: I8cbbce516958030aa4a997d54fc9a95ab5f97dbf
Previous-Reviewed-on: https://gerrit.chromium.org/gerrit/47135
(cherry picked from commit 6693870f00c9380b8adfc6ac61be4d0f49a74fd2)
Reviewed-on: https://gerrit.chromium.org/gerrit/47234
Reviewed-by: Scott Zawalski <scottz@chromium.org>
Tested-by: Scott Zawalski <scottz@chromium.org>
1 file changed