Fix highlight in CombinedChart

[hannesa2]

It needs #665 in advance

[hannesa2]

StartTest_smokeTestStart-25-CombinedChartActivity-CombinedChart-click.png

StartTest_smokeTestStart-25-CombinedChartActivity-CombinedChart-click2020.png

StartTest_smokeTestStart-25-CombinedChartActivity-CombinedChart-click7070.png

[hannesa2]

@Paget96 as #665 is now merged, we see the improvement here.
This was the desired behavior to have an evidence to see that it solves it.

This makes the tests professional and makes sure, that the click event now works for ever (as long as nobody merges stuff too early)