updated flags from false to dicated on www (#16647)

Author: lunaruan

packages/shared/forks/ReactFeatureFlags.www.js

@@ -22,6 +22,8 @@ export const {
   enableUserBlockingEvents,
   disableLegacyContext,
   disableSchedulerTimeoutBasedOnReactExpirationTime,
+  warnAboutStringRefs,
+  warnAboutDefaultPropsOnFunctionComponents,
 } = require('ReactFeatureFlags');
 
 // In www, we have experimental support for gathering data
@@ -81,10 +83,6 @@ export const warnAboutUnmockedScheduler = true;
 
 export const enableSuspenseCallback = true;
 
-export const warnAboutDefaultPropsOnFunctionComponents = false;
-
-export const warnAboutStringRefs = false;
-
 export const flushSuspenseFallbacksInTests = true;
 
 // Flow magic to verify the exports of this file match the original version.