When switching Events or Content reports to a pie or bar chart the metric selection in the report currently only has
Visits as option, which is actually not even available in some of the reports.
Reason is, that selectable columns is filled with defaults if nothing is set.
Note: This might already have been an issue in Matomo 3.x
@sgiehl tested it and worked. However, some system tests are failing. I suppose this is unrelated to this PR? If so feel free to merge.