Support adjusting period of metric log task after initialization

[linyihai]

Describe what this PR does / why we need it

to try solve issue: adjusting period of metric log task after initialization #148

Does this pull request fix one issue?

Describe how you did it

detect the flush interval config then reset the ticker

Describe how to verify it

Special notes for reviews

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
4 out of 5 committers have signed the CLA.

:white_check_mark: louyuting
:white_check_mark: luckyxiaoqiang
:white_check_mark: AlexStocks
:white_check_mark: binbin0325
:x: linyihai

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[sczyh30]

Hi, thanks for contributing. Could you please sign the CLA here? And please make sure the email of your commits match your GitHub email. You may refer to the instruction here, or rebase your commits with the correct email.

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感谢贡献，请将 commit 对应的 email 调整成与 GitHub 的 email 相匹配并 确认一下 CLA。

[louyuting]

@linyihai Could you please fix CI?

[codecov-io]

Codecov Report

Merging #285 into master will decrease coverage by 0.47%. The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master     #285      +/-   ##
==========================================
- Coverage   51.34%   50.86%   -0.48%     
==========================================
  Files          79       79              
  Lines        4024     4050      +26     
==========================================
- Hits         2066     2060       -6     
- Misses       1668     1701      +33     
+ Partials      290      289       -1     

Impacted Files	Coverage Δ
core/config/config.go	20.83% <0.00%> (-0.91%)	:arrow_down:
core/log/metric/aggregator.go	19.23% <0.00%> (-6.64%)	:arrow_down:
api/api.go	20.28% <0.00%> (-14.04%)	:arrow_down:
core/flow/rule.go	19.04% <0.00%> (ø)
core/flow/tc_throttling.go	74.07% <0.00%> (+11.11%)	:arrow_up:

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[linyihai]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution. 3 out of 5 committers have signed the CLA.

✅ sanxun0325 ✅ louyuting ✅ luckyxiaoqiang ❌ linyihai ❌ AlexStocks

linyihai seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account. You have signed the CLA already but the status is still pending? Let us recheck it.

I had signed the CLA. But it still display pending.

[louyuting]

Support for adjusting period does not seem necessary. Maybe we just support stop task is ok?