refactor: allow custom impl of backend realod-to-profile support check (#31048)

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## Summary

In preparation to support reload-to-profile in Fusebox (#31021), we need
a way to check capability of different backends, e.g. web vs React
Native.

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* Default, e.g. existing web impl = no-op
* Custom impl: is called

packages/react-devtools-inline/src/backend.js

@@ -8,6 +8,7 @@ import setupNativeStyleEditor from 'react-devtools-shared/src/backend/NativeStyl
 
 import type {BackendBridge} from 'react-devtools-shared/src/bridge';
 import type {Wall} from 'react-devtools-shared/src/frontend/types';
+import {getIsReloadAndProfileSupported} from 'react-devtools-shared/src/utils';
 
 function startActivation(contentWindow: any, bridge: BackendBridge) {
   const onSavedPreferences = (data: $FlowFixMe) => {
@@ -66,7 +67,7 @@ function finishActivation(contentWindow: any, bridge: BackendBridge) {
 
   const hook = contentWindow.__REACT_DEVTOOLS_GLOBAL_HOOK__;
   if (hook) {
-    initBackend(hook, agent, contentWindow);
+    initBackend(hook, agent, contentWindow, getIsReloadAndProfileSupported());
 
     // Setup React Native style editor if a renderer like react-native-web has injected it.
     if (hook.resolveRNStyle) {