BugFix - Grafana Page Error on AWS instance #856 #1130

[Prantick]

Description

Added explicit gRPC server and frontend client configuration parameters to the Mimir structuredConfig block in both edgenode-observability.tpl and orchestrator-observability.tpl. These settings enhance gRPC communication reliability and performance by controlling keepalive intervals, connection age, and message size limits.

Fixes # (issue)

BugFix - Grafana Page Error on AWS instance #856 #1130

Any Newly Introduced Dependencies

No new 3rd party dependencies were introduced in this change.

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How Has This Been Tested?

• Verified that the new configuration values render correctly in the generated manifests.
• Confirmed that ArgoCD applies the updated templates without errors.
• Observed improved gRPC connection stability in test environments.
• Tested on release-3.1 using AWS instance

Test steps:

1. Deploy updated templates to a test cluster.
2. Check that the new gRPC settings appear in the Mimir configuration.
3. Validate that Mimir pods start and function as expected.

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Checklist:

• I agree to use the APACHE-2.0 license for my code changes
• I have not introduced any 3rd party dependency changes
• I have performed a self-review of my code

[cjnolan]

@Prantick could you update the PR branch name please? It will cause a failure in the CI pre-check when the branch name is checked