Making haptics in new volume dialog slider continuous.

Given the short length of the slider, dragging through its many discrete
steps makes it feel like the slider is actually continuous. Therefore,
we make sure we deliver continous haptics on the vertical volume slider.
In the case of the horizontal sliders in the volume panel, the surface
area is large enough so that the discrete steps are salient in the
dragging motion. Thus, we keep these haptics discrete.

We achieve these behaviors by providing different bundles of
SliderHapticFeedbackConfig and SeekableSliderTrackerConfig objects in a
new VolumeHapticsConfigs data class. Discretized configs are supplied to
the volume sliders in the volume panel, and continuous configs are given
to the vertical volume dialog.

Test: manual. Verified that the volume dialog delivers continuous
  haptics and the volume panel delivers discrete haptics.
Flag: EXEMPT bugfix
Bug: 407025177

Change-Id: I6e9d16f04060af68081f4728a018c862c34dce19