[jaeger] make replicas a Helm value instead of hardcoding it

[lisenet]

What this PR does

Adds a Helm value for allInOne.replicas.

Which issue this PR fixes

• fixes [Feature]: make replicas spec a Helm variable rather than hardcoding to replicas: 1 #493

Checklist

• DCO signed
• Commits are GPG signed
• Chart Version bumped
• Title of the PR starts with chart name ([jaeger] or [jaeger-operator])
• README.md has been updated to match version/contain new values

[pavelnikolov]

@lisenet it doesn't make sense to use the all-in-one Jaeger with more than one replica since the data is in-memory. Therefore, different replicas wouldn't share the data between them. Am I missing something?

[pavelnikolov]

@mehta-ankit does it make sense to have more than one replica of the all-in-one container? I think it doesn't make sense and this PR shouldn't have been merged.

[mehta-ankit]

@mehta-ankit does it make sense to have more than one replica of the all-in-one container? I think it doesn't make sense and this PR shouldn't have been merged.

you do bring up a good point and I thought about it, but since this was a backwards compatible change I went ahead and merged it.

[lisenet]

@pavelnikolov our use case is that we need to deploy it with zero replicas so that no deployment is running but the config is there, and we flip the switch when we run a performance test to gather Istio tracing information. It is currently not possible to do so using the current chart version.

[pavelnikolov]

fyi #499