fix(starfish): Use abs value (#47899)

fixes this thing
![Screenshot 2023-04-25 at 11 55 06
AM](https://user-images.githubusercontent.com/63818634/234334208-ceeb00e0-f0c3-406d-9b1f-a565d59eb424.png)

Author: shruthilayaj

static/app/views/starfish/views/webServiceView/endpointList.tsx

@@ -147,7 +147,7 @@ class EndpointList extends Component<Props, State> {
           <TrendingDuration trendDirection={trendDirection}>
             {tct('([sign][delta])', {
               sign: deltaValue >= 0 ? '+' : '-',
-              delta: formatPercentage(deltaValue, 2),
+              delta: formatPercentage(Math.abs(deltaValue), 2),
             })}
           </TrendingDuration>
         </NumberContainer>