Set layout metrics during initial render of Fabric

Summary:
This diff refactors the initial render of Fabric in order to set the layout metrics as we start the surface.

This prevents to create an additional fabric commit during initial render. Also this migth help fixing T63495589 (I wasn't able to repro T63495589 again when using this diff)

changelog: [Internal][Android] Internal change to reduce the amount of commits during initial render of Fabric

Reviewed By: JoshuaGross

Differential Revision: D21330072

fbshipit-source-id: 758c49b52ea4c12d5623b7c7d68c7318f4a6cd83

ReactAndroid/src/main/java/com/facebook/react/ReactInstanceManager.java

@@ -1150,21 +1150,29 @@ public class ReactInstanceManager {
 
     @Nullable Bundle initialProperties = reactRoot.getAppProperties();
 
-    final int rootTag =
-        uiManager.addRootView(
-            reactRoot.getRootViewGroup(),
-            initialProperties == null
-                ? new WritableNativeMap()
-                : Arguments.fromBundle(initialProperties),
-            reactRoot.getInitialUITemplate());
-    reactRoot.setRootViewTag(rootTag);
+    final int rootTag;
+
     if (reactRoot.getUIManagerType() == FABRIC) {
-      // Fabric requires to call updateRootLayoutSpecs before starting JS Application,
-      // this ensures the root will hace the correct pointScaleFactor.
-      uiManager.updateRootLayoutSpecs(
-          rootTag, reactRoot.getWidthMeasureSpec(), reactRoot.getHeightMeasureSpec());
+      rootTag =
+          uiManager.startSurface(
+              reactRoot.getRootViewGroup(),
+              reactRoot.getJSModuleName(),
+              initialProperties == null
+                  ? new WritableNativeMap()
+                  : Arguments.fromBundle(initialProperties),
+              reactRoot.getWidthMeasureSpec(),
+              reactRoot.getHeightMeasureSpec());
+      reactRoot.setRootViewTag(rootTag);
       reactRoot.setShouldLogContentAppeared(true);
     } else {
+      rootTag =
+          uiManager.addRootView(
+              reactRoot.getRootViewGroup(),
+              initialProperties == null
+                  ? new WritableNativeMap()
+                  : Arguments.fromBundle(initialProperties),
+              reactRoot.getInitialUITemplate());
+      reactRoot.setRootViewTag(rootTag);
       reactRoot.runApplication();
     }
     Systrace.beginAsyncSection(