Introduce getDiffProps for <View> (facebook#45552)

Summary:
Pull Request resolved: facebook#45552

In this diff I'm overriding the getDiffProps for  ViewProps.
The goal is to verify what's the impact of calculating diffs of props in Android, starting with ViewProps.
Once we verify what are the implication we will automatic implement this diffing.

The full implementation of this method will be implemented in the following diffs

changelog: [internal] internal

Reviewed By: NickGerleman

Differential Revision: D59969328

fbshipit-source-id: ce141528581e46e9ced4175dca040ddf8bed5ddb

Author: mdvacca

packages/react-native/ReactCommon/react/renderer/components/view/platform/android/react/renderer/components/view/HostPlatformViewProps.cpp

@@ -133,4 +133,25 @@ SharedDebugStringConvertibleList HostPlatformViewProps::getDebugProps() const {
 }
 #endif
 
+#ifdef ANDROID
+
+folly::dynamic HostPlatformViewProps::getDiffProps(
+    const Props* prevProps) const {
+  folly::dynamic result = folly::dynamic::object();
+
+  static const auto defaultProps = HostPlatformViewProps();
+
+  const HostPlatformViewProps* oldProps = prevProps == nullptr
+      ? &defaultProps
+      : static_cast<const HostPlatformViewProps*>(prevProps);
+
+  if (focusable != oldProps->focusable) {
+    result["focusable"] = focusable;
+  }
+
+  return result;
+}
+
+#endif
+
 } // namespace facebook::react

packages/react-native/ReactCommon/react/renderer/components/view/platform/android/react/renderer/components/view/HostPlatformViewProps.h

@@ -55,6 +55,12 @@ class HostPlatformViewProps : public BaseViewProps {
 #if RN_DEBUG_STRING_CONVERTIBLE
   SharedDebugStringConvertibleList getDebugProps() const override;
 #endif
+
+#ifdef ANDROID
+
+  folly::dynamic getDiffProps(const Props* prevProps) const override;
+
+#endif
 };
 
 } // namespace facebook::react