Add The Ability To Set Log Level

**Is your feature request related to a problem? Please describe.**
Setting PULSAR_LOG_ROOT_LEVEL and PULSAR_ROOT_LOGGER environment variables using configData does not change the log level since it uses the conf/log4j2.yaml .

**Describe the solution you'd like**
Ideally we would be able to only use environment variables, but that will not be possible until pulsar does not depend on the log4j2.yaml file. To get it working in its current state, we could create a ConfigMap with the contents of the logfile, then mount it as a volume and set the PULSAR_LOG_CONF to point to our mounted file instead of conf/log4j2.yaml.

No specific chart file or test is named. Start by tracing how the chart handles PULSAR_LOG_ROOT_LEVEL, PULSAR_ROOT_LOGGER, and PULSAR_LOG_CONF alongside conf/log4j2.yaml; done means the log configuration can be supplied through the requested environment-variable and mounted ConfigMap workflow.

Written by the indexing model from the issue text.