Added OpenTelemetry Initialization action for Dataproc clusters

[shambhavirai16]

• Added OpenTelemetry initialization script for installing and configuring otelcol-contrib agent for monitoring purposes. This enables users to collect and export metrics/logs/traces and supports numerous sinks.
• Support for GCM exporter (enabled by default)
• Support for scraping prometheus metrics from any arbitrary http endpoints passed in prometheus-scrape-endpoints metadata property
• Added README for the new init script

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[jayadeep-jayaraman]

/gcbrun

[shambhavirai16]

/gcbrun