[Predictive Back] Widget to home polish: show extra rows at bottom during animation

1. setClipChildren(false) for WidgetFullSheet and content view during animation
2. setClipToOutline(true) for WidgetsRecyclerView and provide ViewOutlineProvider to expand bottom by 5% of height
3. Override calculateExtraLayoutSpace() for ScrollableLayoutManager
4. Manually modify AbstractSlideInView#mContent's background drawable during scale animation

bug: b/260956481
Test: manual

Change-Id: Ic391639de887cf4a70bc4965dc0b1fd9bc12dd2c

src/com/android/launcher3/allapps/AllAppsGridAdapter.java

@@ -21,7 +21,6 @@ import android.view.View;
 import android.view.ViewGroup;
 import android.view.accessibility.AccessibilityEvent;
 
-import androidx.annotation.Px;
 import androidx.core.view.accessibility.AccessibilityEventCompat;
 import androidx.core.view.accessibility.AccessibilityNodeInfoCompat;
 import androidx.core.view.accessibility.AccessibilityRecordCompat;
@@ -145,19 +144,6 @@ public class AllAppsGridAdapter<T extends Context & ActivityContext> extends
                     cic.isSelected()));
         }
 
-        /**
-         * We need to extend all apps' RecyclerView's bottom by 5% of view height to ensure extra
-         * roll(s) of app icons is rendered at the bottom, so that they can fill the bottom gap
-         * created during predictive back's scale animation from all apps to home.
-         */
-        @Override
-        protected void calculateExtraLayoutSpace(RecyclerView.State state, int[] extraLayoutSpace) {
-            super.calculateExtraLayoutSpace(state, extraLayoutSpace);
-            @Px int extraSpacePx = (int) (getHeight()
-                    * (1 - AllAppsTransitionController.SWIPE_ALL_APPS_TO_HOME_MIN_SCALE) / 2);
-            extraLayoutSpace[1] = Math.max(extraLayoutSpace[1], extraSpacePx);
-        }
-
         /**
          * Returns the number of rows before {@param adapterPosition}, including this position
          * which should not be counted towards the collection info.