fix tuner filter callback scheduler

This fixes multiple issues in filter callback scheduler:
- currently, when mDataSizeDelayInBytes is 0, filter events are sent
every time onFilterEvent is called. When mTimeDelayInMs is set (to
something else than 0), this will falsely override the time delay.
- when datasize delay or time delays are updated, the cv needs to be
notified so the new delay goes into effect right away.
- std::condition_variables *must* make use of a shared variable in order
to prevent lost and spurious wakeups.

Test: atest VtsHalTvTunerTargetTest
Bug: 183057734
Change-Id: I9fb4e87e8ba887f0ce891ccb9981bfa49a3ceada