Ensuring vibration scale is at most 1 in magnetic pull haptics.

After calculations of vibration scale, we make sure that the resulting
scale for haptics is at most 1.0, the maximum value allowed by the
haptics framework.

Test: manual. Verified haptics continue to play correctly in magnetic
  swipes
Flag: EXEMPT bugfix
Bug: 424721504
Change-Id: Ie003be168dac6d5273ec1c45ab52bf47272a811d