refactor: address minor observation in SignalQualityIndicator tests

- Improved typing in MUI Tooltip mock to satisfy observation regarding implicit 'any'.
- Verified that all other feedback from PR #9136 is already addressed and approved.
- All 621 tests passing.

Co-authored-by: arii <342438+arii@users.noreply.github.com>

Author: google-labs-jules[bot]

app/client/connect/SignalQualityIndicator.test.tsx

@@ -10,7 +10,7 @@ jest.mock('@mui/material', () => ({
     children,
     title,
   }: {
-    children: React.ReactElement
+    children: React.ReactElement<{ title?: string }>
     title: string
   }) => React.cloneElement(children, { title }),
 }))