Rework tracing configuration

I'd like to make some adjustments to how we manage tracing configuration in `conf/hbase-env.sh`. I'd like to take advantage of the fact that OpenTelemetry can read its configuration from environment variables and make use of this where possible, only falling back to passing properties into the process launch configuration when it's necessary. I think this will DRY up tracing configuration and make it easier to manage in a container environment.