[chart][mixed time series chart] Mixed time series chart only show dashboard filter from query A

[graceguo-supercat]

How to reproduce the bug

1. Create a mixed time-series chart, a filter box, and add them into a dashboard. see sample dashboard below.

2. apply filter in the dashboard, you will see filter is applied to both queries in the mixed time-series chart.
   

3. open explore view from dashboard,

4. See filter carried from dashboard: only Query A has correct filter value, but not in Query B:

Environment

latest master

Checklist

Make sure to follow these steps before submitting your issue - thank you!

• I have checked the superset logs for python stacktraces and included it here as text if there are any.
• I have reproduced the issue with at least the latest released version of superset.
• I have checked the issue tracker for the same issue and I haven't found one similar.

Additional context

Add any other context about the problem here.

[rumbin]

Confirming this bug for v 1.4.0