[fix][misc] Honor dynamic log levels in log4j2.yaml

[nodece]

Motivation

When the log levels (pulsar.log.level and pulsar.log.root.level) are modified in the conf/log4j2.yaml during runtime, the change is not reflected in the logs as expected.

I found the pulsar script always passes the pulsar.log.level and pulsar.log.root.level, which led to this issue.

Modifications

• Removed the error environment variable from the pulsar/Dockerfile.
• A condition was added to include the -Dpulsar.log.level only if PULSAR_LOG_LEVEL is defined.
• A condition was added to include the -Dpulsar.log.root.level only if PULSAR_LOG_ROOT_LEVEL is defined, and ensured PULSAR_LOG_ROOT_LEVEL fallback to PULSAR_LOG_LEVEL if not defined.

Documentation

• doc
• doc-required
• doc-not-needed
• doc-complete