fix(module:carousel): fix carousel autoplay bug

[vthinkxie]

close #1242

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: N/A

What is the new behavior?

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

[codecov]

Codecov Report

Merging #1309 into master will decrease coverage by 0.01%.
The diff coverage is 92.3%.

@@            Coverage Diff             @@
##           master    #1309      +/-   ##
==========================================
- Coverage   97.25%   97.23%   -0.02%     
==========================================
  Files         191      191              
  Lines        7928     7928              
  Branches     1040     1041       +1     
==========================================
- Hits         7710     7709       -1     
  Misses         25       25              
- Partials      193      194       +1

Impacted Files	Coverage Δ
components/carousel/nz-carousel.component.ts	95.53% <92.3%> (-0.9%)	⬇️

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