Issues#29015 - Saved chart should load settings

Use the %ARGS which gets updated with data from $saved_search
and still honor the request payload in case the user wants to
update the chart.

The _right_ order is something like:
  1. Saved search values
  2. or GET/POST parameters
  3. or parameters on last Search/Build.html page
  4. or some sane defaults
Merge branch '4.2/chart-ui-gc-settings' into 4.2-trunk