Dont fail on the unresolved hostname

[justinlin-linkedin]

Summary

If we have an unresolvable hostname from property store data node configs, we will fail helix cluster manager and kill all the frontend and server instance when booting up the process. Let's don't do this. We should create an alert for those hosts.

Testing Done

No need for tests

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 68.75000% with 5 lines in your changes missing coverage. Please review.

Project coverage is 69.89%. Comparing base (52ba813) to head (82359b6).
Report is 192 commits behind head on master.

Files with missing lines	Patch %	Lines
...m/github/ambry/clustermap/HelixClusterManager.java	61.53%	5 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #3024      +/-   ##
============================================
+ Coverage     64.24%   69.89%   +5.64%     
- Complexity    10398    12276    +1878     
============================================
  Files           840      901      +61     
  Lines         71755    75973    +4218     
  Branches       8611     9081     +470     
============================================
+ Hits          46099    53098    +6999     
+ Misses        23004    20102    -2902     
- Partials       2652     2773     +121     

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

🚀 New features to boost your workflow:

• ❄ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.