Remove createReactClass from ProgressBarAndroidExample (#21874)

Summary:
Related to #21581

This PR was already opened here https://github.com/facebook/react-native/pull/21600 but seems to be inactive.

Remove createReactClass from ProgressBarAndroidExample.

- `yarn run flow` && `yarn run flow-check-android` succeed.
- RNTester app ProgressBarAndroidExample on Android.

[GENERAL] [ENHANCEMENT] [ProgressBarAndroidExample.android.js] - rm createReactClass
Pull Request resolved: https://github.com/facebook/react-native/pull/21874

Reviewed By: TheSavior

Differential Revision: D12827689

Pulled By: RSNara

fbshipit-source-id: 46c70ea67dddf5d928fe936a28ef4a0a929d127f

Libraries/Components/ProgressBarAndroid/ProgressBarAndroid.android.js

@@ -19,7 +19,7 @@ import type {ViewProps} from 'ViewPropTypes';
 
 const AndroidProgressBar = requireNativeComponent('AndroidProgressBar');
 
-type Props = $ReadOnly<{|
+export type ProgressBarAndroidProps = $ReadOnly<{|
   ...ViewProps,
 
   /**
@@ -83,7 +83,7 @@ type Props = $ReadOnly<{|
  * ```
  */
 const ProgressBarAndroid = (
-  props: Props,
+  props: ProgressBarAndroidProps,
   forwardedRef: ?React.Ref<'AndroidProgressBar'>,
 ) => {
   return <AndroidProgressBar {...props} ref={forwardedRef} />;
@@ -98,4 +98,6 @@ ProgressBarAndroidToExport.defaultProps = {
   animating: true,
 };
 
-module.exports = (ProgressBarAndroidToExport: Class<NativeComponent<Props>>);
+module.exports = (ProgressBarAndroidToExport: Class<
+  NativeComponent<ProgressBarAndroidProps>,
+>);