Extract interpolators and durations out of LaunchAnimator

This CL extracts the durations and interpolators from LaunchAnimator so
that we can use different durations and interpolators in the
DialogLaunchAnimator (compared to the ActivityLaunchAnimator).

This CL is a no-op and does not change the interpolators and durations
yet. Those will be changed in a follow-up CL.

Bug: 208241926
Test: Manual
Change-Id: Ic4d7def45cabc8c73700efcec67706eaf81b2b9e