Enhancements:

• Enable users to override iKey, cloud role name and cloud role instance per telemetry #1630.
• Add preview instrumentations for javaHttpClient, rabbitmq, and jaxws #1650.
• Add a new env var called APPLICATIONINSIGHTS_RP_CONFIGURATION_FILE.
• Add cloud role name and instance to applicationinsights-rp.json configuration.
• Improve agent start up time.

Bug Fixes:

• Fix duplicate headers #1640.