refactor:added validation in otherCmsUid state variable

Author: AishDani

ui/src/components/ContentMapper/index.tsx

@@ -265,7 +265,7 @@ const ContentMapper = forwardRef(({handleStepChange}: contentMapperProps, ref: R
     label: contentTypeMapped?.[otherCmsTitle] ?? `Select ${isContentType ? 'Content Type' : 'Global Field'} from Existing Stack`,
     value: contentTypeMapped?.[otherCmsTitle] ?? `Select ${isContentType ? 'Content Type' : 'Global Field'} from Existing Stack`,
   });
-  const [otherCmsUid, setOtherCmsUid] = useState<string>(contentTypes[0]?.otherCmsUid);
+  const [otherCmsUid, setOtherCmsUid] = useState<string>(contentTypes?.[0]?.otherCmsUid);
 
   const [active, setActive] = useState<number | null>(0);
 
@@ -2423,4 +2423,4 @@ const ContentMapper = forwardRef(({handleStepChange}: contentMapperProps, ref: R
 });
 
 ContentMapper.displayName = 'ContentMapper';
-export default ContentMapper;
+export default ContentMapper;