[MINOR] Improvement(dashboard): Support display human-readable time format for app page

[maobaolong]

What changes were proposed in this pull request?

Display the human-readable time format in application page.

Why are the changes needed?

A long type timestamp really hard to get information from it.

Does this PR introduce any user-facing change?

Format the update time to human-readable.

How was this patch tested?

[rickyma]

Good catch! Please remove useless auto-generated information in the description of this PR.

Also, you can attach the picture in the comment of this PR. Don't attach it into the description, because the description will be committed as git commit message. So the picture will not be displayed.

[github-actions[bot]]

Test Results

 2 657 files  ±0   2 657 suites  ±0   5h 31m 12s :stopwatch: -16s    946 tests ±0     945 :white_check_mark: ±0   1 :zzz: ±0  0 :x: ±0  11 789 runs  ±0  11 774 :white_check_mark: ±0  15 :zzz: ±0  0 :x: ±0 

Results for commit a7707081. ± Comparison against base commit 441fad03.

:recycle: This comment has been updated with latest results.

[maobaolong]

@xianjingfeng Thanks for you suggestion commit, I've accepted all of them, PTAL.

[rickyma]

@xianjingfeng Please approve it.

[rickyma]

@maobaolong Please delete the auto-generated info like (Please outline the changes and how this PR fixes the issue.) in the description. Thanks.

[maobaolong]

@rickyma Done.