Fix starting window problems.

Three problems fixed:
1. When one Activity took over for another Activity not all of the
starting window state was being copied over. Now copying over more
parameters.

2. When the visibility of an Activity was being changed the dummy
animation was overwriting the existing animation. If that animation
was the starting window animating then it started over when the
dummy animation was assigned. Now the dummy animation no longer
replaces an existing starting window animation.

3. The test for whether to animate away the starting window only
looked to see if the Activity had already drawn a window but did
not include the starting window. This caused the starting window
to immediately be hidden when the Activity was removed if no
windows were drawn, thereby exposing the fading window behind.
Now the starting window is included in the hasAppShownWindows test
and is animated away if it is exposed.

Fixes bug 6691421.

Change-Id: I4d32a1546c201652574a44d9e7f2752f1f1eb5a6