Split ActivityLaunchAnimator (1/2)

This CL splits ActivityLaunchAnimator by extracting common logic into
LaunchAnimator. The goal of this CL is to be able to reuse the
LaunchAnimator logic for dialog launches.

This CL also improves GhostedViewLaunchAnimator such that it also works
with:
 * launch containers that are not located at (0, 0).
 * ghosted views that move.

Test: atest ActivityLaunchAnimatorTest
Bug: 193634619
Change-Id: Ic05603600d4a7d4e27182c79bef54286087d00d0