Lazy load ConfigUtil

[lonre]

prevent ConfigUtil init when ApolloApplicationContextInitializer initialized,
That is too early.

This issue caused by commit 6d50ca8

What's the purpose of this PR

XXXXX

Which issue(s) this PR fixes:

Fixes #

Brief changelog

XXXXX

Follow this checklist to help us incorporate your contribution quickly and easily:

• Read the Contributing Guide before making this pull request.
• Write a pull request description that is detailed enough to understand what the pull request does, how, and why.
• Write necessary unit tests to verify the code.
• Run mvn clean test to make sure this pull request doesn't break anything.
• Update the CHANGES log.

[codecov-commenter]

Codecov Report

Merging #3864 (0d6c29b) into master (02c43dd) will decrease coverage by 0.04%.
The diff coverage is 100.00%.

@@             Coverage Diff              @@
##             master    #3864      +/-   ##
============================================
- Coverage     50.18%   50.14%   -0.05%     
+ Complexity     2468     2464       -4     
============================================
  Files           483      483              
  Lines         14921    14921              
  Branches       1520     1520              
============================================
- Hits           7488     7482       -6     
- Misses         6908     6910       +2     
- Partials        525      529       +4     

Impacted Files	Coverage Δ
...ring/boot/ApolloApplicationContextInitializer.java	94.33% <100.00%> (ø)
...apollo/spring/config/PropertySourcesProcessor.java	92.72% <100.00%> (ø)
...rk/apollo/spring/property/SpringValueRegistry.java	83.33% <0.00%> (-5.56%)	⬇️
...nfigservice/service/AccessKeyServiceWithCache.java	82.65% <0.00%> (-2.05%)	⬇️
.../framework/apollo/spring/property/SpringValue.java	87.71% <0.00%> (-1.76%)	⬇️
.../apollo/internals/RemoteConfigLongPollService.java	77.71% <0.00%> (-0.61%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 02c43dd...0d6c29b. Read the comment docs.

[lonre]

since #3800 introduced,

Spring Boot project start failed with

18:53:31.374 [main] WARN com.ctrip.framework.foundation.internals.provider.DefaultApplicationProvider - app.id is not available from System Property and /META-INF/app.properties. It is set to null
18:53:31.386 [main] INFO com.ctrip.framework.foundation.internals.provider.DefaultServerProvider - Environment is set to null. Because it is not available in either (1) JVM system property 'env', (2) OS env variable 'ENV' nor (3) property 'env' from the properties InputStream.
18:53:31.386 [main] DEBUG com.ctrip.framework.foundation.internals.provider.DefaultServerProvider - Data Center is set to null. Because it is not available in either (1) JVM system property 'idc', (2) OS env variable 'IDC' nor (3) property 'idc' from the properties InputStream.
2021-07-31 18:53:32.939  WARN [,,] 4429 --- [           main] c.c.f.a.internals.ConfigServiceLocator   : Located config services from apollo.config-service configuration: http://xxx.xxx.xxx.xxx, will not refresh config services from remote meta service!
2021-07-31 18:53:32.940  WARN [,,] 4429 --- [           main] c.c.f.a.i.LocalFileConfigRepository      : Sync config from upstream repository class com.ctrip.framework.apollo.internals.RemoteConfigRepository failed, reason: Load Apollo Config failed - appId: ApolloNoAppIdPlaceHolder, cluster: default, namespace: application, url: http://xxx.xxx.xxx.xxx/configs/ApolloNoAppIdPlaceHolder/default/application?ip=0.0.0.0 [Cause: [status code: 404] Could not find config for namespace - appId: ApolloNoAppIdPlaceHolder, cluster: default, namespace: application, please check whether the configs are released in Apollo!]
2021-07-31 18:53:32.940  WARN [,,] 4429 --- [           main] c.c.f.a.i.LocalFileConfigRepository      : Sync config from upstream repository class com.ctrip.framework.apollo.internals.RemoteConfigRepository failed, reason: Load Apollo Config failed - appId: ApolloNoAppIdPlaceHolder, cluster: default, namespace: application, url: http://xxx.xxx.xxx.xxx/configs/ApolloNoAppIdPlaceHolder/default/application?ip=0.0.0.0 [Cause: [status code: 404] Could not find config for namespace - appId: ApolloNoAppIdPlaceHolder, cluster: default, namespace: application, please check whether the configs are released in Apollo!]

[nobodyiam]

Is it necessary to change this logic too? I noticed this line of code was introduced 3 years ago..

[lonre]

currently it's ok if we keep the origin logic, but i thinks it's more safe if we will make this change

[nobodyiam]

LGTM