Mark IntBufferBatchMountItem as nullsafe (#44540)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/44540

Noticed when running `arc nn`

> Advice xplat/js/react-native-github/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/fabric/mounting/mountitems/IntBufferBatchMountItem.java:39
> [Class has 0 issues and can be marked Nullsafe] Congrats! `IntBufferBatchMountItem` is free of nullability issues. Mark it `Nullsafe(Nullsafe.Mode.LOCAL)` to prevent regressions.

Changelog: [Internal]

Reviewed By: rshest

Differential Revision: D57249958

fbshipit-source-id: d38559a3fafae0ad778c19dd85c5da610a650d7c

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/fabric/FabricUIManager.java

@@ -776,9 +776,12 @@ public class FabricUIManager
   @AnyThread
   @ThreadConfined(ANY)
   private MountItem createIntBufferBatchMountItem(
-      int rootTag, int[] intBuffer, Object[] objBuffer, int commitNumber) {
+      int rootTag, @Nullable int[] intBuffer, @Nullable Object[] objBuffer, int commitNumber) {
     return MountItemFactory.createIntBufferBatchMountItem(
-        rootTag, intBuffer, objBuffer, commitNumber);
+        rootTag,
+        intBuffer == null ? new int[0] : intBuffer,
+        objBuffer == null ? new Object[0] : objBuffer,
+        commitNumber);
   }
 
   /**

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/fabric/mounting/mountitems/IntBufferBatchMountItem.java

@@ -11,8 +11,8 @@ import static com.facebook.react.fabric.FabricUIManager.ENABLE_FABRIC_LOGS;
 import static com.facebook.react.fabric.FabricUIManager.IS_DEVELOPMENT_ENVIRONMENT;
 import static com.facebook.react.fabric.mounting.mountitems.FabricNameComponentMapping.getFabricComponentName;
 
-import androidx.annotation.NonNull;
 import com.facebook.common.logging.FLog;
+import com.facebook.infer.annotation.Nullsafe;
 import com.facebook.proguard.annotations.DoNotStrip;
 import com.facebook.react.bridge.ReactMarker;
 import com.facebook.react.bridge.ReactMarkerConstants;
@@ -35,6 +35,7 @@ import com.facebook.systrace.Systrace;
  * allocations in C++ and JNI round-trips.
  */
 @DoNotStrip
+@Nullsafe(Nullsafe.Mode.LOCAL)
 final class IntBufferBatchMountItem implements BatchMountItem {
   static final String TAG = IntBufferBatchMountItem.class.getSimpleName();
 
@@ -55,8 +56,8 @@ final class IntBufferBatchMountItem implements BatchMountItem {
   private final int mSurfaceId;
   private final int mCommitNumber;
 
-  private final @NonNull int[] mIntBuffer;
-  private final @NonNull Object[] mObjBuffer;
+  private final int[] mIntBuffer;
+  private final Object[] mObjBuffer;
 
   private final int mIntBufferLen;
   private final int mObjBufferLen;
@@ -68,8 +69,8 @@ final class IntBufferBatchMountItem implements BatchMountItem {
     mIntBuffer = intBuf;
     mObjBuffer = objBuf;
 
-    mIntBufferLen = mIntBuffer != null ? mIntBuffer.length : 0;
-    mObjBufferLen = mObjBuffer != null ? mObjBuffer.length : 0;
+    mIntBufferLen = mIntBuffer.length;
+    mObjBufferLen = mObjBuffer.length;
   }
 
   private void beginMarkers(String reason) {
@@ -91,7 +92,7 @@ final class IntBufferBatchMountItem implements BatchMountItem {
   }
 
   @Override
-  public void execute(@NonNull MountingManager mountingManager) {
+  public void execute(MountingManager mountingManager) {
     SurfaceMountingManager surfaceMountingManager = mountingManager.getSurfaceManager(mSurfaceId);
     if (surfaceMountingManager == null) {
       FLog.e(

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/fabric/mounting/mountitems/MountItemFactory.kt

@@ -63,8 +63,8 @@ public object MountItemFactory {
   @JvmStatic
   public fun createIntBufferBatchMountItem(
       surfaceId: Int,
-      intBuf: IntArray?,
-      objBuf: Array<Any?>?,
+      intBuf: IntArray,
+      objBuf: Array<Any?>,
       commitNumber: Int
   ): MountItem = IntBufferBatchMountItem(surfaceId, intBuf, objBuf, commitNumber)
 }