Update ActivePwle description for amplitude values

Update description to clarify that the value 1 should map to the maximum
output acceleration supported by the device at any frequency, not exclusively
to the one at resonant frequency.

Also add information linking the  ActivePwle input parameters of composePwle
to the output values returned by getBandwidthAmplitudeMap, and update
the bandwidth description as well.

Change-Id: Id6e02c5d323aec57db7e7127e219a9705d0289a3
Fix: 199753151
Test: VtsHalVibratorTargetTest