[maps] fix radius label contrast (#104182) (#104707)

* [maps] fix radius label contrast

* Update x-pack/plugins/maps/public/connected_components/mb_map/draw_control/draw_control.tsx

Co-authored-by: Elizabet Oliveira <elizabet.oliveira@elastic.co>

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>
Co-authored-by: Elizabet Oliveira <elizabet.oliveira@elastic.co>

Co-authored-by: Nathan Reese <reese.nathan@gmail.com>
Co-authored-by: Elizabet Oliveira <elizabet.oliveira@elastic.co>

x-pack/plugins/maps/public/connected_components/mb_map/draw_control/draw_control.tsx

@@ -134,7 +134,7 @@ export class DrawControl extends Component<Props> {
         },
         paint: {
           'text-color': '#fbb03b',
-          'text-halo-color': 'rgba(255, 255, 255, 1)',
+          'text-halo-color': 'rgba(0, 0, 0, 1)',
           'text-halo-width': 2,
         },
       });