Estimate animation duration for AVD and AnimationDrawable

For Android S, we use the API windowSplashScreenAnimationDuration to
know the duration of the animatable icon would be, however, developers
can be confused to thought that this API is used to declare the
duration of splash screen.
To get the real duration of the animatable icon, if it is an AVD or
AnimationDrawable, try to get the animation duration from it.

Test: atest StartingSurfaceDrawerTests SplashscreenTests
Bug: 211707095

Change-Id: Ia3f8c5cd50bab164360e07d9ced87ff7f4321e96