Add fadingEdgeLength prop to android scroll view props (facebook#54164)

Summary:
Pull Request resolved: facebook#54164

Adding `fadingEdgeLength` prop to the Android scroll view props together with prop diffing support for Props 2.0.

Changelog: [Internal]

Differential Revision: D84788963

fbshipit-source-id: 6cf8011816311797fe0d805f68ccb026e32d7bff

Author: Nick Lefever

packages/react-native/ReactCommon/react/renderer/components/scrollview/platform/android/react/renderer/components/scrollview/HostPlatformScrollViewProps.cpp

@@ -38,7 +38,16 @@ HostPlatformScrollViewProps::HostPlatformScrollViewProps(
                     rawProps,
                     "nestedScrollEnabled",
                     sourceProps.nestedScrollEnabled,
-                    true))
+                    true)),
+      fadingEdgeLength(
+          ReactNativeFeatureFlags::enableCppPropsIteratorSetter()
+              ? sourceProps.fadingEdgeLength
+              : convertRawProp(
+                    context,
+                    rawProps,
+                    "fadingEdgeLength",
+                    sourceProps.fadingEdgeLength,
+                    nullptr))
 
 {}
 
@@ -57,6 +66,7 @@ void HostPlatformScrollViewProps::setProp(
   switch (hash) {
     RAW_SET_PROP_SWITCH_CASE_BASIC(sendMomentumEvents);
     RAW_SET_PROP_SWITCH_CASE_BASIC(nestedScrollEnabled);
+    RAW_SET_PROP_SWITCH_CASE_BASIC(fadingEdgeLength);
   }
 }
 
@@ -348,6 +358,10 @@ folly::dynamic HostPlatformScrollViewProps::getDiffProps(
     result["nestedScrollEnabled"] = nestedScrollEnabled;
   }
 
+  if (fadingEdgeLength != oldProps->fadingEdgeLength) {
+    result["fadingEdgeLength"] = fadingEdgeLength;
+  }
+
   return result;
 }
 

packages/react-native/ReactCommon/react/renderer/components/scrollview/platform/android/react/renderer/components/scrollview/HostPlatformScrollViewProps.h

@@ -32,6 +32,7 @@ class HostPlatformScrollViewProps : public BaseScrollViewProps {
 
   bool sendMomentumEvents{};
   bool nestedScrollEnabled{};
+  folly::dynamic fadingEdgeLength{};
 
 #pragma mark - DebugStringConvertible