SF: stay with the current mode when all votes are NO_PREF

The current code intended to do the same, however because of
the workaround for b/266481656 it didn't.

Bug: 333443503
Test: Settings -> About Phone and observe the refresh rate indicator
Flag: EXEMPT bugfix
Change-Id: Ic48c31af6562bb29be45f1fbab4abebb2788b551