TimeSeries showLegend defaults to False

[Gnappuraz]

What you expected to happen?

A TimeSeries object that has any of legendDisplayMode, legendPlacement, legendCalcs set, should show the legend panel automatically, or allow the flag to be set as ctor parameter.

What happened?

If any of the above is set, the legend becomes hidden.

If manually enabled it will show the legend correctly set with all its attributes.

How to reproduce it?

TimeSeries(
        title="some title",
        dataSource="any test datasource",
        targets="any test target",
        legendDisplayMode="table",
        legendPlacement="bottom",
        legendCalcs=["mean", "lastNotNull", "max"])

Adding

extraJson={
            "options": {
                "legend": {
                    "showLegend": True,
                }
            }
        }

as ctor param shows the legend correctly.

If confirmed I'll be happy to contribute with a PR to fix the issue.