Update AcitvityIndicator spec default value (#41638)

Summary:
Update AcitvityIndicator spec default value. https://reactnative.dev/docs/activityindicator

## Changelog:

[GENERAL] [FIXED] - Update AcitvityIndicator spec default value

Pull Request resolved: #41638

Test Plan:
Codegen generates native code correctly.
![image](https://github.com/facebook/react-native/assets/5061845/ae087e06-d996-4aa1-bd41-da84bc50bdd7)

Reviewed By: christophpurrer

Differential Revision: D51584438

Pulled By: javache

fbshipit-source-id: ee0df8314597457fd35f86008a96264be3f761ba

packages/react-native/Libraries/Components/ActivityIndicator/ActivityIndicatorViewNativeComponent.js

@@ -21,16 +21,16 @@ type NativeProps = $ReadOnly<{|
   /**
    * Whether the indicator should hide when not animating (true by default).
    *
-   * See https://reactnative.dev/docs/activityindicator#hideswhenstopped
+   * See https://reactnative.dev/docs/activityindicator#hideswhenstopped-ios
    */
-  hidesWhenStopped?: WithDefault<boolean, false>,
+  hidesWhenStopped?: WithDefault<boolean, true>,
 
   /**
    * Whether to show the indicator (true, the default) or hide it (false).
    *
    * See https://reactnative.dev/docs/activityindicator#animating
    */
-  animating?: WithDefault<boolean, false>,
+  animating?: WithDefault<boolean, true>,
 
   /**
    * The foreground color of the spinner (default is gray).