fix(module: calendar): fix calendar timepicker display title error bug

[3fuyu]

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-mobile/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 #444 into master will decrease coverage by 0.07%.
The diff coverage is 18.18%.

@@            Coverage Diff            @@
##           master    #444      +/-   ##
=========================================
- Coverage   85.77%   85.7%   -0.08%     
=========================================
  Files         314     314              
  Lines        7623    7631       +8     
  Branches     1082    1084       +2     
=========================================
+ Hits         6539    6540       +1     
- Misses        655     662       +7     
  Partials      429     429

Impacted Files	Coverage Δ
components/calendar/util/index.ts	52.38% <12.5%> (-24.55%)	⬇️
components/calendar/calendar.component.ts	71.42% <33.33%> (ø)	⬆️

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[3fuyu]

#432