Store last successful MS host for agent reconnection fallback

[Pearl1594]

Description

The issue is that once a bad hosts configuration update made, there's no way to get the Agents back in Up state without SSH-ing on each of them and manually updating the agent.properties file (because they're not listening to any new update from a control plane, since they're not connected anymore).

Types of changes

• Breaking change (fix or feature that would cause existing functionality to change)
• New feature (non-breaking change which adds functionality)
• Bug fix (non-breaking change which fixes an issue)
• Enhancement (improves an existing feature and functionality)
• Cleanup (Code refactoring and cleanup, that may add test cases)
• Build/CI
• Test (unit or integration test code)

Feature/Enhancement Scale or Bug Severity

Feature/Enhancement Scale

• Major
• Minor

Screenshots (if appropriate):

How Has This Been Tested?

How did you try to break this feature and the system with this change?

[codecov]

Codecov Report

❌ Patch coverage is 51.85185% with 13 lines in your changes missing coverage. Please review.
✅ Project coverage is 16.33%. Comparing base (6136ac9) to head (d42e2aa).

Files with missing lines	Patch %	Lines
...gent/src/main/java/com/cloud/agent/AgentShell.java	65.00%	5 Missing and 2 partials ⚠️
agent/src/main/java/com/cloud/agent/Agent.java	0.00%	6 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               4.20   #14002      +/-   ##
============================================
+ Coverage     16.32%   16.33%   +0.01%     
- Complexity    13556    13564       +8     
============================================
  Files          5669     5669              
  Lines        501399   501425      +26     
  Branches      60902    60904       +2     
============================================
+ Hits          81847    81913      +66     
+ Misses       410390   410341      -49     
- Partials       9162     9171       +9     

Flag	Coverage Δ
uitests	4.14% <ø> (ø)
unittests	17.19% <51.85%> (+0.01%)	⬆️

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[DaanHoogland]

it seems we have been working in the same area @Pearl1594 , #14000 is about agent rebalancing for local agents and #14001 about rebalancing remote agents. Can you have a look at those as well, please?

[Pearl1594]

It seems so - but they don't clash. I can have a look at them. Thanks @DaanHoogland

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
40.5% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[Pearl1594]

@blueorangutan package

[blueorangutan]

@Pearl1594 a [SL] Jenkins job has been kicked to build packages. It will be bundled with KVM, XenServer and VMware SystemVM templates. I'll keep you posted as I make progress.

[blueorangutan]

Packaging result [SF]: ✔️ el8 ✔️ el9 ✔️ el10 ✔️ debian ✔️ suse15. SL-JID 19030