fix: only treat null/undefined as falsy when rendering XComEntry (apa…

…che#42199) (apache#42213)

fix: only treat null, undefined or NaN as NULL in XComEntry render

fix: use coalescing nullish check + isNaN

fix: only treat null/undefined as falsy when rendering XComEntry
(cherry picked from commit ade9de1)

Co-authored-by: Detlev V. <[email protected]>

airflow/www/static/js/dag/details/taskInstance/Xcom/XcomEntry.tsx

@@ -67,7 +67,7 @@ const XcomEntry = ({
         No value found for XCom key
       </Alert>
     );
-  } else if (!xcom.value) {
+  } else if (xcom.value === undefined || xcom.value === null) {
     content = (
       <Alert status="info">
         <AlertIcon />