Move UnionDecorationHandler to Launcher

- Create base SectionDecorationInfo.java and RecyclerViewAnimationController.java
- SearchTransitionController now inherits from RecyclerViewAnimationController where RecyclerViewAnimationController will control
animation for private space

Bug: 299294792
Test: Verified SearchTransitionController didn't regress by turning off BACKGROUND_DRAWABLES flag.
- Verified QL highlight still works
- video: https://drive.google.com/file/d/15yjBWofebn6m7VgEnLK6kEYqhC_adJQ3/view?usp=sharing

Flag: None
Change-Id: If34f4bb199be0e113485279931d2927cb9fad397

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

@@ -36,7 +36,11 @@ import android.content.Context;
 import android.graphics.Canvas;
 import android.util.AttributeSet;
 import android.util.Log;
+import android.view.View;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.core.util.Consumer;
 import androidx.recyclerview.widget.RecyclerView;
 
 import com.android.launcher3.DeviceProfile;
@@ -57,6 +61,7 @@ public class AllAppsRecyclerView extends FastScrollRecyclerView {
     protected static final String TAG = "AllAppsRecyclerView";
     private static final boolean DEBUG = false;
     private static final boolean DEBUG_LATENCY = Utilities.isPropertyEnabled(SEARCH_LOGGING);
+    private Consumer<View> mChildAttachedConsumer;
 
     protected final int mNumAppsPerRow;
     private final AllAppsFastScrollHelper mFastScrollHelper;
@@ -282,6 +287,22 @@ public class AllAppsRecyclerView extends FastScrollRecyclerView {
         }
     }
 
+    /**
+     * This will be called just before a new child is attached to the window. Passing in null will
+     * remove the consumer.
+     */
+    protected void setChildAttachedConsumer(@Nullable Consumer<View> childAttachedConsumer) {
+        mChildAttachedConsumer = childAttachedConsumer;
+    }
+
+    @Override
+    public void onChildAttachedToWindow(@NonNull View child) {
+        if (mChildAttachedConsumer != null) {
+            mChildAttachedConsumer.accept(child);
+        }
+        super.onChildAttachedToWindow(child);
+    }
+
     @Override
     public int getScrollBarTop() {
         return ActivityContext.lookupContext(getContext()).getAppsView().isSearchSupported()