Some overview scrim and status bar color adjustments

- Replace UI_STATE_OVERVIEW with UI_STATE_FULLSCREEN_TASK. Overview no
  longer needs it's own status bar treatment as it's handled by
  ScrimView already. So remove instances of UI_STATE_OVERVIEW and
  replace some with UI_STATE_FULLSCREEN_TASK if a TaskView is behind
  the status bar.
- Add ScrimView to fallback recents activity.
- Remove scrim from Background state, don't fade it in until the
  gesture ends to RECENTS.

Test: watch scrim and status bar colors during the following
- Swipe up to home (no scrim, status bar matches task at first but
  then wallpaper once task isn't overlapping status bar)
- Swipe up to overview (no scrim until let go to overview, status
  bar matches task at first, then wallpaper after not overlapping,
  then scrim once it's 90% opacity)
- Quick switch from home (scrim fades in, status bar matches once
  it reaches 90% opacity)
- Quick switch from app (no scrim, status bar matches center task)
- Repeat above for 3P launcher and 2 button mode

Fixes: 185681676
Fixes: 185286870
Change-Id: I9e5c292cc734e714169b9cc8268e8dad4e868aca

quickstep/src/com/android/quickstep/fallback/FallbackRecentsStateController.java

@@ -20,6 +20,7 @@ import static com.android.launcher3.states.StateAnimationConfig.ANIM_OVERVIEW_MO
 import static com.android.launcher3.states.StateAnimationConfig.ANIM_OVERVIEW_SCALE;
 import static com.android.launcher3.states.StateAnimationConfig.ANIM_OVERVIEW_TRANSLATE_X;
 import static com.android.launcher3.states.StateAnimationConfig.ANIM_OVERVIEW_TRANSLATE_Y;
+import static com.android.launcher3.states.StateAnimationConfig.ANIM_WORKSPACE_SCRIM_FADE;
 import static com.android.launcher3.states.StateAnimationConfig.SKIP_OVERVIEW;
 import static com.android.quickstep.views.RecentsView.ADJACENT_PAGE_OFFSET;
 import static com.android.quickstep.views.RecentsView.FULLSCREEN_PROGRESS;
@@ -95,5 +96,8 @@ public class FallbackRecentsStateController implements StateHandler<RecentsState
         setter.setFloat(mRecentsView, FULLSCREEN_PROGRESS, state.isFullScreen() ? 1 : 0, LINEAR);
         setter.setFloat(mRecentsView, RECENTS_GRID_PROGRESS,
                 state.displayOverviewTasksAsGrid(mActivity.getDeviceProfile()) ? 1f : 0f, LINEAR);
+
+        setter.setViewBackgroundColor(mActivity.getScrimView(), state.getScrimColor(mActivity),
+                config.getInterpolator(ANIM_WORKSPACE_SCRIM_FADE, LINEAR));
     }
 }