When comparing stream bitrate with available (allocated) bandwidth,
we need to take the playback speed into account. In the current
calculation, this can happen on both sides of the equation, but we
take the time to first byte into account, we need to move the speed
into the available, allocated bandwidth.
This change moves the speed adjustment to the bandwidth calculation
side in AdaptiveTrackSelection.
PiperOrigin-RevId: 362540071
