RefreshRatePolicy: a few fixes

RefreshRatePolicyTest had some tests that checks for an app override
vote but use the same vote as the deny list or camera that they are
trying to override. This CL fixes all tests and the implementation
to return the expected values.

Test: atest RefreshRatePolicyTest FrameRateSelectionPriorityTests
Bug: 192413241
Change-Id: I0f37f856947ea39de6ea11c77c11771cbca29b49