Globally disable LayoutAnimation during Snapshot Tests

Summary: LayoutAnimation is one source of flakiness in SSTs. Disable it globally in the SST apps.

Reviewed By: ejanzer

Differential Revision: D13791987

fbshipit-source-id: 0ebfd79fb31d235680c0d84f4b06d5a98c35260a

Libraries/LayoutAnimation/LayoutAnimation.js

@@ -10,6 +10,7 @@
 
 'use strict';
 
+import Platform from 'Platform';
 const UIManager = require('UIManager');
 
 type Type =
@@ -42,13 +43,15 @@ function configureNext(
   config: LayoutAnimationConfig,
   onAnimationDidEnd?: Function,
 ) {
-  UIManager.configureNextLayoutAnimation(
-    config,
-    onAnimationDidEnd ?? function() {},
-    function() {
-      /* unused */
-    },
-  );
+  if (!Platform.isTesting) {
+    UIManager.configureNextLayoutAnimation(
+      config,
+      onAnimationDidEnd ?? function() {},
+      function() {
+        /* unused */
+      },
+    );
+  }
 }
 
 function create(