[VRR] Ensure refresh rate is reset when only categories are voted

Fixes: 338219378

When frame rate is boosted due to velocity or other reasons,
when the velocity drops to 0 and the category is the only thing
that votes, the refresh rate should be reset.

Test: new test, manual testing
Change-Id: Ia3c0537b35a99f98e447cdcbc0eacf5f8efe0f80