fix: do not start subscription-polling when shield feature is disabled cp-13.8.0 (#37476)

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## **Description**
fix: do not start subscription-polling when shield feature is disabled

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CHANGELOG entry: fixed subscription-polling when shield feature is
disabled

## **Related issues**

Fixes: #37485

## **Manual testing steps**

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<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> Start subscriptions polling only when Shield feature and basic
functionality are enabled, alongside existing account/sign-in/unlock
checks.
> 
> - **Shield subscription polling**:
> - In `ui/contexts/shield/shield-subscription.tsx`, only dispatch
`subscriptionsStartPolling()` when `isMetaMaskShieldFeatureEnabled` and
`isBasicFunctionalityEnabled` are true (in addition to existing
`selectedAccount`, `isSignedIn`, `isUnlocked`).
>   - Update the effect dependency array to include these flags.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
02c9334. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: lwin-kyaw

ui/contexts/shield/shield-subscription.tsx

@@ -127,11 +127,24 @@ export const ShieldSubscriptionProvider: React.FC = ({ children }) => {
   ]);
 
   useEffect(() => {
-    if (selectedAccount && isSignedIn && isUnlocked) {
+    if (
+      isMetaMaskShieldFeatureEnabled &&
+      isBasicFunctionalityEnabled &&
+      selectedAccount &&
+      isSignedIn &&
+      isUnlocked
+    ) {
       // start polling for the subscriptions
       dispatch(subscriptionsStartPolling());
     }
-  }, [isSignedIn, selectedAccount, dispatch, isUnlocked]);
+  }, [
+    isMetaMaskShieldFeatureEnabled,
+    isSignedIn,
+    selectedAccount,
+    dispatch,
+    isUnlocked,
+    isBasicFunctionalityEnabled,
+  ]);
 
   const resetShieldEntryModalShownStatus = useCallback(() => {
     if (!isShieldSubscriptionActive) {