fix: missing default values for system settings

[ruibaby]

What type of PR is this?

/kind bug
/area core
/milestone 2.16.x

What this PR does / why we need it:

补充缺失的系统设置默认值。

Does this PR introduce a user-facing change?

修复系统设置未保存导致无法正常注册的问题

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 56.47%. Comparing base (5fdf6c0) to head (e9e00e0).
Report is 226 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #6035      +/-   ##
============================================
- Coverage     56.91%   56.47%   -0.44%     
- Complexity     3319     3541     +222     
============================================
  Files           587      622      +35     
  Lines         18968    20961    +1993     
  Branches       1401     1478      +77     
============================================
+ Hits          10795    11838    +1043     
- Misses         7594     8523     +929     
- Partials        579      600      +21     

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[JohnNiang]

/lgtm

/cherrypick release-2.16

[f2c-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: JohnNiang

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[JohnNiang]

/cherrypick release-2.16

[halo-dev-bot]

@JohnNiang: once the present PR merges, I will cherry-pick it on top of release-2.16 in a new PR and assign it to you.

In response to this:

/cherrypick release-2.16

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[halo-dev-bot]

@JohnNiang: new pull request created: #6036

In response to this:

/cherrypick release-2.16

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.