[APM] Display service icons without filled background (#145329)

## Summary
## Before





https://user-images.githubusercontent.com/3369346/202012360-9694c183-e826-4eac-aced-d7c19c0b26db.mov


![image](https://user-images.githubusercontent.com/3369346/202148711-7aea3d69-936b-4112-94d2-a6a0429f8891.png)

## After 


https://user-images.githubusercontent.com/3369346/202012369-4387db32-369b-441f-aeea-78cfbdceda16.mov


![image](https://user-images.githubusercontent.com/3369346/202148764-f0d83140-10e6-4b01-b4e6-5b3c88efae00.png)


![image](https://user-images.githubusercontent.com/3369346/202149004-ab60b385-a403-4165-aa88-646f6a2b4047.png)

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>

x-pack/plugins/apm/public/components/shared/service_icons/icon_popover.tsx

@@ -55,8 +55,7 @@ export function IconPopover({
       ownFocus={false}
       button={
         <StyledButtonIcon
-          display="fill"
-          color="ghost"
+          color="text"
           onClick={onClick}
           iconType={icon.type}
           iconSize={icon.size ?? 'l'}