[jaeger] Add securityContext for spark cron job

[brainstorm82]

What this PR does

Adding possibility to configure securityContext for spark CronJob

Which issue this PR fixes

• Checklist

• [x] DCO signed

• [x] Commits are GPG signed

• [x] Chart Version bumped

• [x] Title of the PR starts with chart name ([jaeger] or [jaeger-operator])

• [x] README.md has been updated to match version/contain new values

[pavelnikolov]

@brainstorm82 could you, please, GPG-sign your commit?

[brainstorm82]

Added GPG signing