Restore scroll state of scroll view on mount (#54000)

Summary:
Pull Request resolved: #54000

Update the scroll view manager to load the fabric state and restore the scroll position and scroll away top padding on mount. Restoring the scroll view happens in the react scroll view state setter, which gets called by the `ReactScrollViewHelper` with the deserialized state provided on mount.

The state loading will happen only until the scroll view itself submits a new state to Fabric (due to scrolling). This guarantees that we only restore the initial state on mount.

This diff also updates the scroll away top padding setter to support setting a new value without triggering a fabric state update.

Changelog: [Internal]

Reviewed By: rshest

Differential Revision: D83247016

fbshipit-source-id: 7ae44b9f69c58da9e5163574073767aea2713b62

Author: Nick Lefever

packages/react-native/ReactAndroid/api/ReactAndroid.api

@@ -5779,6 +5779,7 @@ public class com/facebook/react/views/scroll/ReactScrollView : android/widget/Sc
 	public fun setReactScrollViewScrollState (Lcom/facebook/react/views/scroll/ReactScrollViewHelper$ReactScrollViewScrollState;)V
 	public fun setRemoveClippedSubviews (Z)V
 	public fun setScrollAwayTopPaddingEnabledUnstable (I)V
+	public fun setScrollAwayTopPaddingEnabledUnstable (IZ)V
 	public fun setScrollEnabled (Z)V
 	public fun setScrollEventThrottle (I)V
 	public fun setScrollPerfTag (Ljava/lang/String;)V

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactScrollView.java

@@ -18,6 +18,7 @@
 import android.content.Context;
 import android.graphics.Canvas;
 import android.graphics.Color;
+import android.graphics.Point;
 import android.graphics.Rect;
 import android.graphics.drawable.ColorDrawable;
 import android.graphics.drawable.Drawable;
@@ -1439,6 +1440,10 @@ public void setBorderStyle(@Nullable String style) {
    * style. `translateY` must never be set from ReactJS while using this feature!
    */
   public void setScrollAwayTopPaddingEnabledUnstable(int topPadding) {
+    setScrollAwayTopPaddingEnabledUnstable(topPadding, true);
+  }
+
+  public void setScrollAwayTopPaddingEnabledUnstable(int topPadding, boolean updateState) {
     int count = getChildCount();
 
     Assertions.assertCondition(
@@ -1458,7 +1463,9 @@ public void setScrollAwayTopPaddingEnabledUnstable(int topPadding) {
       setPadding(0, 0, 0, topPadding);
     }
 
-    updateScrollAwayState(topPadding);
+    if (updateState) {
+      updateScrollAwayState(topPadding);
+    }
     setRemoveClippedSubviews(mRemoveClippedSubviews);
   }
 
@@ -1470,6 +1477,12 @@ private void updateScrollAwayState(int scrollAwayPaddingTop) {
   @Override
   public void setReactScrollViewScrollState(ReactScrollViewScrollState scrollState) {
     mReactScrollViewScrollState = scrollState;
+    if (ReactNativeFeatureFlags.enableViewCulling()) {
+      setScrollAwayTopPaddingEnabledUnstable(scrollState.getScrollAwayPaddingTop(), false);
+
+      Point scrollPosition = scrollState.getLastStateUpdateScroll();
+      scrollTo(scrollPosition.x, scrollPosition.y);
+    }
   }
 
   @Override

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactScrollViewManager.kt

@@ -384,6 +384,9 @@ constructor(private val fpsListener: FpsListener? = null) :
       stateWrapper: StateWrapper,
   ): Any? {
     view.setStateWrapper(stateWrapper)
+    if (ReactNativeFeatureFlags.enableViewCulling()) {
+      ReactScrollViewHelper.loadFabricScrollState(view, stateWrapper)
+    }
     return null
   }