fix: replace end of navigation init and UIStartup span (#12489)

## **Description**

Replace navigation init and UIStartup Span

* It seems that the span was ending in the finally of appTriggeredAuth,
which means that it was ending after Byometrics of the user which was
causing this issue (5 minutes long span)

* Moving it to an useEffect that will only trigger the end of the span
when the navigator is defined and there is no prevNavigator ref will
means that the traces will end when the biometrics are actually
triggered instead of when it is completed

## **Related issues**

Fixes:

## **Manual testing steps**

1. Go to this page...
2.
3.

## **Screenshots/Recordings**

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before and after of your change. -->

### **Before**

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### **After**

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## **Pre-merge author checklist**

- [ ] I’ve followed [MetaMask Contributor
Docs](https://github.com/MetaMask/contributor-docs) and [MetaMask Mobile
Coding
Standards](https://github.com/MetaMask/metamask-mobile/blob/main/.github/guidelines/CODING_GUIDELINES.md).
- [ ] I've completed the PR template to the best of my ability
- [ ] I’ve included tests if applicable
- [ ] I’ve documented my code using [JSDoc](https://jsdoc.app/) format
if applicable
- [ ] I’ve applied the right labels on the PR (see [labeling
guidelines](https://github.com/MetaMask/metamask-mobile/blob/main/.github/guidelines/LABELING_GUIDELINES.md)).
Not required for external contributors.

## **Pre-merge reviewer checklist**

- [ ] I've manually tested the PR (e.g. pull and build branch, run the
app, test code being changed).
- [ ] I confirm that this PR addresses all acceptance criteria described
in the ticket it closes and includes the necessary testing evidence such
as recordings and or screenshots.

app/components/Nav/App/index.js

@@ -608,6 +608,13 @@ const App = (props) => {
     }
   };
 
+  useEffect(() => {
+    if (prevNavigator.current || !navigator) return;
+
+    endTrace({ name: TraceName.NavInit });
+    endTrace({ name: TraceName.UIStartup });
+  }, [navigator]);
+
   useEffect(() => {
     if (prevNavigator.current || !navigator) return;
     const appTriggeredAuth = async () => {
@@ -650,15 +657,9 @@ const App = (props) => {
         );
       }
     };
-    appTriggeredAuth()
-      .catch((error) => {
-        Logger.error(error, 'App: Error in appTriggeredAuth');
-      })
-      .finally(() => {
-        endTrace({ name: TraceName.NavInit });
-
-        endTrace({ name: TraceName.UIStartup });
-      });
+    appTriggeredAuth().catch((error) => {
+      Logger.error(error, 'App: Error in appTriggeredAuth');
+    });
   }, [navigator, queueOfHandleDeeplinkFunctions]);
 
   const handleDeeplink = useCallback(({ error, params, uri }) => {