Filters applied to visualizations are lost when viewing on a dashboard

[stacey-gammon]

To repro:

1. Create a pie chart with a filter on it, say bytes:0
2. Add that visualization to a dashboard. See all bytes.

Confirmed broken in master, and works in 6.2.3. Probably broken in 6.3 and a blocker.

cc @elastic/kibana-visualizations

[stacey-gammon]

Have not confirmed but I suspect #17123

I think this line is overriding existing filter pills

See before that line:

And after that line, the Watch output:

And if I comment it out, it works (well the filter pill is applied, though commenting it out probably breaks something else).

This also clearly identified a gap in our tests. _dashboard_queries functional tests have tests for queries on a visualization, and links to saved searches, but none for a filter pill.

cc @timroes