Add extraScrapeConfigs in prometheus-config-values.yaml

[jenting]

Make sure it's tested

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Describe your changes

Add extraScrapeConfigs in prometheus-config-values.yaml

Related Issues / Projects

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fix #852

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Label	Description
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Blocked	Work can not proceed because other work has not been completed, PR can not be merged (code has not been merged but documentation is ready)
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v3/v4/v4.x	Which version of the release the PR should be merged into, this can be multiple versions, please set the "Backport" label if it needs to go into a previous release
Needs Review	Some details of the PR are known to be incomplete and must be discussed with other engineers before merging (if possible assign reviewers or cc mention in comments), PR can not be merged

[jenting]

Merge remote branch maintenance/CaaS4 to fix conflicts.