Testing initial value for 0-duration animations

To ensure consistency with the pre-N animation behavior, we are testing
the following:

- For animations that have a duration of 0, we set the animator's value
  to the end value when start() is called.
- For animations with a duration > 0 but with the duration scale of 0
  applied, we set the animator's value to its start value when start()
  gets called.

Change-Id: I666105e0677c6cfdeddb11b483d71dab978adc11