Cancel & restart auth ripple if already running

Instead of completely ignoring the request to
startUnlockedRipple if the auth ripple is still running.

This prevents quick subsequent authentications from not
showing a new ripple animation.

Fixes: 263565188
Test: Authenticate with UDFPS multiple times in a row, observe
auth ripple always shows

Change-Id: I74095fcb493352f68c9c9715aab4db8d1a2925ae