Provide a way to set the logging level on smartrouter image

Today, there is no easy way to configure logging level on smartrouter image.
Would be good if we have the option to just set an env like LOG_LEVEL=debug

and the image is correctly configured, the logging.properties file needs t be created and the system property added:

-Djava.util.logging.config.file=/etc/logging/logging.properties

Today it can be done by creating a config map, example:

handlers= java.util.logging.ConsoleHandler
.level= ALL
java.util.logging.ConsoleHandler.level= DEBUG
java.util.logging.ConsoleHandler.formatter= java.util.logging.SimpleFormatter
org.kie = TRACE

And set the JAVA_OPTS env adding the config-map location., e.g.

-Djava.util.logging.config.file=/etc/logging/logging.properties