fix: The env should override flags

[cloudxxx8]

Close #747

If your build fails due to your commit message not passing the build checks, please review the guidelines here: https://github.com/edgexfoundry/go-mod-bootstrap/blob/main/.github/Contributing.md

PR Checklist

Please check if your PR fulfills the following requirements:

• I am not introducing a breaking change (if you are, flag in conventional commit message with BREAKING CHANGE: describing the break)
• I am not introducing a new dependency (add notes below if you are)
• I have added unit tests for the new feature or bug fix (if not, why?)
• I have fully tested (add details below) this the new feature or bug fix (if not, why?)
• I have opened a PR for the related docs change (if not, why?)
  docs: Add new EDGEX_OVERWRITE_CONFIG env edgex-docs#1366

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

Attention: Patch coverage is 0% with 19 lines in your changes missing coverage. Please review.

Project coverage is 54.63%. Comparing base (6f7163b) to head (fe8b0f6).

Files	Patch %	Lines
bootstrap/config/config.go	0.00%	13 Missing ⚠️
bootstrap/environment/variables.go	0.00%	6 Missing ⚠️

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #750      +/-   ##
==========================================
- Coverage   54.77%   54.63%   -0.15%     
==========================================
  Files          32       32              
  Lines        2724     2731       +7     
==========================================
  Hits         1492     1492              
- Misses       1130     1137       +7     
  Partials      102      102              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[jinlinGuan]

LGTM