fix(module:time-picker): hidden clear icon when disabled

[stygian-desolator]

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
#5980

What is the new behavior?

time picker will hidden clear icon when disabled

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 #5990 into master will increase coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #5990      +/-   ##
==========================================
+ Coverage   89.95%   89.96%   +0.01%     
==========================================
  Files         465      465              
  Lines       14046    14046              
  Branches     2308     2308              
==========================================
+ Hits        12635    12637       +2     
+ Misses        863      862       -1     
+ Partials      548      547       -1     

Impacted Files	Coverage Δ
components/time-picker/time-picker.component.ts	85.93% <ø> (ø)
components/tabs/tab-nav-bar.component.ts	82.33% <0.00%> (+0.70%)	⬆️

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[wenqi73]

LGTM. @stygian-desolator Good job!