feat(ui): Add sign to release 0 diff (#27910)

static/app/components/notAvailable.tsx

@@ -6,11 +6,12 @@ import {defined} from 'app/utils';
 
 type Props = {
   tooltip?: React.ReactNode;
+  className?: string;
 };
 
-function NotAvailable({tooltip}: Props) {
+function NotAvailable({tooltip, className}: Props) {
   return (
-    <Wrapper>
+    <Wrapper className={className}>
       <Tooltip title={tooltip} disabled={!defined(tooltip)}>
         {'\u2014'}
       </Tooltip>

static/app/views/releases/detail/overview/releaseComparisonChart/index.tsx

@@ -766,7 +766,11 @@ function ReleaseComparisonChart({
     return diff ? (
       <Change color={defined(diffColor) ? diffColor : undefined}>
         {diff}{' '}
-        {defined(diffDirection) && <IconArrow direction={diffDirection} size="xs" />}
+        {defined(diffDirection) ? (
+          <IconArrow direction={diffDirection} size="xs" />
+        ) : (
+          <StyledNotAvailable />
+        )}
       </Change>
     ) : null;
   }
@@ -1050,4 +1054,8 @@ const ChartTable = styled(PanelTable)`
   }
 `;
 
+const StyledNotAvailable = styled(NotAvailable)`
+  display: inline-block;
+`;
+
 export default ReleaseComparisonChart;