Set enableViewTransition to dynamic for www (facebook#32306)

Unblocks internal experimentation

Author: jackpope

packages/react/index.fb.js

@@ -37,6 +37,7 @@ export {
   unstable_LegacyHidden,
   unstable_Scope,
   unstable_SuspenseList,
+  unstable_ViewTransition,
   unstable_TracingMarker,
   unstable_useCacheRefresh,
   use,

packages/shared/forks/ReactFeatureFlags.www-dynamic.js

@@ -39,6 +39,7 @@ export const enableSiblingPrerendering = __VARIANT__;
 export const enableUseResourceEffectHook = __VARIANT__;
 export const enableRemoveConsolePatches = __VARIANT__;
 export const enableFastAddPropertiesInDiffing = __VARIANT__;
+export const enableViewTransition = __VARIANT__;
 
 // TODO: These flags are hard-coded to the default values used in open source.
 // Update the tests so that they pass in either mode, then set these

packages/shared/forks/ReactFeatureFlags.www.js

@@ -38,6 +38,7 @@ export const {
   enableOwnerStacks,
   enableRemoveConsolePatches,
   enableFastAddPropertiesInDiffing,
+  enableViewTransition,
 } = dynamicFeatureFlags;
 
 // On WWW, __EXPERIMENTAL__ is used for a new modern build.
@@ -60,7 +61,6 @@ export const enableLegacyFBSupport = true;
 export const enableYieldingBeforePassive = false;
 
 export const enableThrottledScheduling = false;
-export const enableViewTransition = false;
 
 export const enableHydrationLaneScheduling = true;