Created shell cmd to vibrate.

Syntax: cmd vibrator vibrate duration [description]

Where duration is is the 'duration' in ms (maximum is 200) and
'description' is an optional description for the stats.

BUG: 34346796
Test: manual verification

Change-Id: I3c548af22108dfcb1a1f6e71e3f1a3194d3f0e3c