fix #4365 correcting backoff interval

[shawkins]

Description

I introduced a regression in #4365 with the refactoring of the exponential backoff - the interval was not carried forward.

Another, optional, change is to add exceptions that preserve for blocking request stacktraces - that seems better than just the underlying stacktrace which will just be from the httpclient layer.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• Feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change
• Chore (non-breaking change which doesn't affect codebase;
  test, version modification, documentation, etc.)

Checklist

• Code contributed by me aligns with current project license: Apache 2.0
• I Added CHANGELOG entry regarding this change
• I have implemented unit tests to cover my changes
• I have added/updated the javadocs and other documentation accordingly
• No new bugs, code smells, etc. in SonarCloud report
• I tested my code in Kubernetes
• I tested my code in OpenShift

[manusa]

tests are failing :(

[shawkins]

tests are failing :(

Right, the exception wrapping is not fully baked.

[shawkins]

@manusa should be better now.

[sonarcloud]

SonarCloud Quality Gate failed.   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

75.0% Coverage
0.0% Duplication