Improve Fabric debug logging (#39778)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/39778

Used with `IS_DEVELOPMENT_ENVIRONMENT` and `ReactFeatureFlags.enableFabricLogs`.

Changelog: [Internal]

Reviewed By: NickGerleman

Differential Revision: D49864983

fbshipit-source-id: bf912abd765ff74e9ed8b94571293f79458feca2

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

@@ -83,4 +83,18 @@ public class StateWrapperImpl implements StateWrapper {
       mHybridData.resetNative();
     }
   }
+
+  @Override
+  public String toString() {
+    if (mDestroyed) {
+      return "<destroyed>";
+    }
+
+    ReadableNativeMap map = getStateDataImpl();
+    if (map == null) {
+      return "<unexpected null>";
+    }
+
+    return map.toString();
+  }
 }

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

@@ -247,12 +247,13 @@ public class MountItemDispatcher {
     // If there are MountItems to dispatch, we make sure all the "pre mount items" are executed
     // first
     Collection<MountItem> preMountItemsToDispatch = getAndResetPreMountItems();
-
     if (preMountItemsToDispatch != null) {
       Systrace.beginSection(
           Systrace.TRACE_TAG_REACT_JAVA_BRIDGE, "FabricUIManager::mountViews preMountItems");
-
       for (MountItem preMountItem : preMountItemsToDispatch) {
+        if (ENABLE_FABRIC_LOGS) {
+          printMountItem(preMountItem, "dispatchMountItems: Executing preMountItem");
+        }
         executeOrEnqueue(preMountItem);
       }
 
@@ -330,11 +331,8 @@ public class MountItemDispatcher {
         }
 
         if (ENABLE_FABRIC_LOGS) {
-          printMountItem(
-              preMountItemToDispatch,
-              "dispatchPreMountItems: Dispatching PreAllocateViewMountItem");
+          printMountItem(preMountItemToDispatch, "dispatchPreMountItems");
         }
-
         executeOrEnqueue(preMountItemToDispatch);
       }
     } finally {

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

@@ -242,7 +242,7 @@ final class IntBufferBatchMountItem implements BatchMountItem {
             StateWrapper state = castToState(mObjBuffer[j++]);
             String stateString =
                 IS_DEVELOPMENT_ENVIRONMENT
-                    ? (state != null ? state.getStateData().toString() : "<null>")
+                    ? (state != null ? state.toString() : "<null>")
                     : "<hidden>";
             s.append(String.format("UPDATE STATE [%d]: %s\n", mIntBuffer[i++], stateString));
           } else if (type == INSTRUCTION_UPDATE_LAYOUT) {