[AC-4543] chore: update default visibility status of banner (#402)

## Changes
- update default visibility status of banner

ticket: [AC-4543]

## Additional Notes
- 

## Checklist
Before requesting a code review, please check the following:
- [x] **[Required]** CI has passed all checks.
- [x] **[Required]** A self-review has been conducted to ensure there
are no minor mistakes.
- [x] **[Required]** Unnecessary comments/debugging code have been
removed.
- [x] **[Required]** All requirements specified in the ticket have been
accurately implemented.
- [x] Ensure the ticket has been updated with the sprint, status, and
story points.


[AC-4543]:
https://sendbird.atlassian.net/browse/AC-4543?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

src/components/ui/PoweredByBanner.tsx

@@ -15,9 +15,6 @@ export function PoweredByBanner() {
   }
 
   return <Banner />;
-  // const inputElement = document.querySelector('.sendbird-message-input-wrapper');
-  //
-  // return inputElement ? ReactDOM.createPortal(<Banner />, inputElement) : null;
 }
 
 const InnerContainer = styled.div<{ chatBottomBackgroundColor?: string }>`

src/utils/index.ts

@@ -185,7 +185,7 @@ export function hideChatBottomBanner(sdk: SendbirdChat): boolean {
     return applicationAttributes.includes(REMOVE_POWERED_BY);
   }
 
-  return false;
+  return true;
 }
 
 export const replaceWithRegex = <T>(