Fix Flow type for React Native (#17992)

Author: gaearon

packages/react-native-renderer/src/ReactNativeComponent.js

@@ -41,16 +41,12 @@ export default function(
    *
    * @abstract
    */
-  class ReactNativeComponent<Props, State = void> extends React.Component<
-    Props,
-    State,
-  > {
+  class ReactNativeComponent<Props> extends React.Component<Props> {
     /**
      * Due to bugs in Flow's handling of React.createClass, some fields already
      * declared in the base class need to be redeclared below.
      */
     props: Props;
-    state: State;
 
     /**
      * Removes focus. This is the opposite of `focus()`.

packages/react-native-renderer/src/ReactNativeTypes.js

@@ -137,7 +137,7 @@ type SecretInternalsFabricType = {
  * Provide minimal Flow typing for the high-level RN API and call it a day.
  */
 export type ReactNativeType = {
-  NativeComponent: _InternalReactNativeComponentClass<{...}>,
+  NativeComponent: typeof ReactNativeComponent,
   findHostInstance_DEPRECATED(
     componentOrHandle: any,
   ): ?ElementRef<HostComponent<mixed>>,
@@ -157,7 +157,7 @@ export type ReactNativeType = {
 };
 
 export type ReactFabricType = {
-  NativeComponent: _InternalReactNativeComponentClass<{...}>,
+  NativeComponent: typeof ReactNativeComponent,
   findHostInstance_DEPRECATED(componentOrHandle: any): ?HostComponent<mixed>,
   findNodeHandle(componentOrHandle: any): ?number,
   dispatchCommand(handle: any, command: string, args: Array<any>): void,