Pass correct action name in the props callback

Summary:
JS side expects the property name to be "actionName", and this change updates it to that.

Changelog:
[iOS][Fixed] - Use actionName in accessibility event callback

Reviewed By: JoshuaGross

Differential Revision: D28645999

fbshipit-source-id: 0e7a6c3e6c1b6c998f4b53fd89c744c84083dfb1

Author: Andrei Shikov

ReactCommon/react/renderer/components/view/ViewEventEmitter.cpp

@@ -15,7 +15,7 @@ namespace react {
 void ViewEventEmitter::onAccessibilityAction(const std::string &name) const {
   dispatchEvent("accessibilityAction", [name](jsi::Runtime &runtime) {
     auto payload = jsi::Object(runtime);
-    payload.setProperty(runtime, "action", name);
+    payload.setProperty(runtime, "actionName", name);
     return payload;
   });
 }