fix(module:descriptions): nzStringTemplateOutlet title style error

[OriginRing]

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
[ ] No

Other information

[zorro-bot]

This preview will be available after the AzureCI is passed.

[codecov]

Codecov Report

Merging #7704 (a52ec6c) into master (41b56e4) will increase coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #7704      +/-   ##
==========================================
+ Coverage   92.02%   92.04%   +0.02%     
==========================================
  Files         502      502              
  Lines       16759    16759              
  Branches     2636     2636              
==========================================
+ Hits        15422    15426       +4     
+ Misses       1069     1064       -5     
- Partials      268      269       +1     

Impacted Files	Coverage Δ
components/descriptions/descriptions.component.ts	100.00% <ø> (ø)
components/table/src/table-style.service.ts	94.82% <0.00%> (-1.73%)	⬇️
components/tabs/tab-nav-bar.component.ts	87.94% <0.00%> (+0.70%)	⬆️
components/table/src/table/tr-measure.component.ts	91.30% <0.00%> (+4.34%)	⬆️
components/table/src/table/tbody.component.ts	100.00% <0.00%> (+11.11%)	⬆️

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[wzhudev]

LGTM. Thanks.