fix: adding missing examples for bubble chart, bullet chart, calendar heatmap chart and country map chart in the gallery

[yash-samsung]

SUMMARY

Adding examples for bubble chart, bullet chart, calendar heatmap chart and country map chart which were missing in the gallery.

BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF

Before:

(Please note that text in red 'No Example' just to show/visualize that there are no examples. In actual, it remains empty)

After:

Before there was no example at the time of selecting the chart type from gallery, where in after image example can be seen in the lower right 'Examples' section. Examples will also be reflected the same way for bullet chart, calendar heatmap chart and country map chart.

TESTING INSTRUCTIONS

At the time of selecting a chart type from the gallery, example will be visible for bubble chart, bullet chart, calendar heatmap chart and country map chart as seen in the after screenshot above.

ADDITIONAL INFORMATION

• Has associated issue: Fixes a part of [Gallery] Some chart type in gallery do not have example #16707
• Required feature flags:
• Changes UI: Only example images will be loaded on the UI. It won't change anything the way user interacts with 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

[github-actions]

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[codecov]

Codecov Report

Merging #22523 (3eaea0d) into master (9b26794) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master   #22523   +/-   ##
=======================================
  Coverage   66.90%   66.90%           
=======================================
  Files        1851     1851           
  Lines       70696    70696           
  Branches     7764     7764           
=======================================
  Hits        47299    47299           
  Misses      21375    21375           
  Partials     2022     2022           

Flag	Coverage Δ
javascript	53.85% <ø> (ø)

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

Impacted Files	Coverage Δ
.../plugins/legacy-plugin-chart-calendar/src/index.js	66.66% <ø> (ø)
...ugins/legacy-plugin-chart-country-map/src/index.js	66.66% <ø> (ø)
...ugins/legacy-preset-chart-nvd3/src/Bubble/index.js	66.66% <ø> (ø)
...ugins/legacy-preset-chart-nvd3/src/Bullet/index.js	66.66% <ø> (ø)

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[villebro]

Thanks for adding these missing examples! LGTM