Enable disableStringRefs and enableRefAsProp for React Native (Me…

…ta) (#29177)

## Summary

Enables the `disableStringRefs` and `enableRefAsProp` feature flags for
React Native (Meta).

## How did you test this change?

```
$ yarn test
$ yarn flow fabric
```

packages/shared/forks/ReactFeatureFlags.native-fb-dynamic.js

@@ -20,10 +20,8 @@
 export const alwaysThrottleRetries = __VARIANT__;
 export const consoleManagedByDevToolsDuringStrictMode = __VARIANT__;
 export const disableDefaultPropsExceptForClasses = __VARIANT__;
-export const disableStringRefs = __VARIANT__;
 export const enableAddPropertiesFastPath = __VARIANT__;
 export const enableDeferRootSchedulingToMicrotask = __VARIANT__;
 export const enableFastJSX = __VARIANT__;
 export const enableInfiniteRenderLoopDetection = __VARIANT__;
-export const enableRefAsProp = __VARIANT__;
 export const passChildrenWhenCloningPersistedNodes = __VARIANT__;

packages/shared/forks/ReactFeatureFlags.native-fb.js

@@ -22,12 +22,10 @@ export const {
   alwaysThrottleRetries,
   consoleManagedByDevToolsDuringStrictMode,
   disableDefaultPropsExceptForClasses,
-  disableStringRefs,
   enableAddPropertiesFastPath,
   enableDeferRootSchedulingToMicrotask,
   enableFastJSX,
   enableInfiniteRenderLoopDetection,
-  enableRefAsProp,
   passChildrenWhenCloningPersistedNodes,
 } = dynamicFlags;
 
@@ -95,6 +93,9 @@ export const disableClientCache = true;
 
 export const enableServerComponentLogs = true;
 
+export const enableRefAsProp = true;
+export const disableStringRefs = true;
+
 export const enableReactTestRendererWarning = false;
 export const disableLegacyMode = false;
 export const disableDOMTestUtils = false;