opentelemetry-collector: update the self metrics after UTF-8 support was added

[ridwanmsharif]

Fixes #833

Depends on the corresponding OTel PR: GoogleCloudPlatform/otlp-k8s-ingest#73

[yqlu]

1. Is there a project you can add me to (google ldap yql) to verify this dashboard config?

2. This seems like a breaking change in that if the users had the old / existing version of the OTel collectors and didn't update, these charts wouldn't show info. At least it looks like this is a sample dashboard that is static the moment it is copied into the project, not a configured integration dashboard that will self-update the moment you push this change. That said, do you think it's worthwhile to put a note in the dashboard description or in a text widget on the dashboard that this dashboard supports OTel collectors with version > xxx?