fix(legacy-plugin-chart-sunburst): linear color scheme not work when secondary metric is provided

[stephenLYZ]

SUMMARY

In the sunburst chart, there is a color policy that normally uses the category color, but when second metric value is provided and is different from the first metric value, the gradient color is used. The category color was previously introduced in color consistency, but the gradient failed in the scenario described above, so we fix it here.

• Normally, category colors are used and the color scheme control is displayed
• When the second metric value is provided and differs from the first metric value, the gradient color is used and the gradient color control is displayed

BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF

after

2022-05-31.12.03.50.mov

TESTING INSTRUCTIONS

ADDITIONAL INFORMATION

• Has associated issue: Sunburst is not using linear color scheme when secondary metric is provided #20150
• Required feature flags:
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)
  • Migration is atomic, supports rollback & is backwards-compatible
  • Confirm DB migration upgrade and downgrade tested
  • Runtime estimates and downtime expectations provided
• Introduces new feature or API
• Removes existing feature or API

[codecov]

Codecov Report

Merging #20221 (8cb8f5a) into master (c8fe518) will decrease coverage by 0.00%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master   #20221      +/-   ##
==========================================
- Coverage   66.47%   66.46%   -0.01%     
==========================================
  Files        1727     1727              
  Lines       64724    64728       +4     
  Branches     6822     6824       +2     
==========================================
  Hits        43024    43024              
- Misses      19969    19973       +4     
  Partials     1731     1731              

Flag	Coverage Δ
javascript	51.33% <0.00%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...ugins/legacy-plugin-chart-sunburst/src/Sunburst.js	0.00% <0.00%> (ø)
...s/legacy-plugin-chart-sunburst/src/controlPanel.ts	20.00% <0.00%> (-80.00%)	⬇️

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[zhaoyongjie]

Codes LGTM, but when I tested locally, I faced a different error after applying multiple columns(Hierarchy). Maybe a separate PR is needed.