fix(module:dropdown): close menu when click again (#6353)

[xiejay97]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/NG-ZORRO/ng-zorro-antd/blob/master/CONTRIBUTING.md#commit
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[x] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Documentation content changes
[ ] Application (the showcase website) / infrastructure changes
[ ] Other... Please describe:

What is the current behavior?

Issue Number: resolve #6353

What is the new behavior?

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

[zorro-bot]

This preview will be available after the AzureCI is passed.

[codecov]

Codecov Report

Merging #6354 (13e8ff0) into master (8233dc4) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #6354   +/-   ##
=======================================
  Coverage   89.88%   89.88%           
=======================================
  Files         478      478           
  Lines       15270    15275    +5     
  Branches     2326     2326           
=======================================
+ Hits        13725    13730    +5     
  Misses        929      929           
  Partials      616      616           

Impacted Files	Coverage Δ
components/dropdown/dropdown.directive.ts	88.77% <100.00%> (ø)
components/modal/utils.ts	100.00% <0.00%> (ø)
components/modal/modal-types.ts	100.00% <0.00%> (ø)
components/upload/upload.component.ts	94.35% <0.00%> (ø)
components/upload/upload-list.component.ts	95.86% <0.00%> (ø)
components/modal/modal-container.component.ts	100.00% <0.00%> (ø)
...ponents/modal/modal-confirm-container.component.ts	100.00% <0.00%> (ø)
components/core/environments/environment.ts
components/core/environments/environment.test.ts	100.00% <0.00%> (ø)
components/date-picker/date-picker.component.ts	93.37% <0.00%> (+0.04%)	⬆️
... and 3 more

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[vthinkxie]

Hi
some ci was failed, could you plz rebase onto master and try again?