Add method for passing environment variables to accumulo-env.sh

[t92549]

Currently, one environment variable is explicitly added to the accumulo-env.sh from the tserver/statefulset.yaml:

gaffer-docker/kubernetes/accumulo/templates/tserver/statefulset.yaml

Lines 37 to 46 in 266e451

	spec:
	containers:
	- name: accumulo-tserver
	image: {{ .Values.image.repository }}:{{ .Values.image.tag }}
	imagePullPolicy: {{ .Values.image.pullPolicy }}
	args:
	- tserver
	env:
	- name: ACCUMULO_CONF_DIR
	value: {{ .Values.config.path }}

However, that file uses lots of environment variables to set a lot of things:

gaffer-docker/kubernetes/accumulo/config/accumulo-env.sh

Lines 34 to 41 in 266e451

	test -z "$ACCUMULO_TSERVER_OPTS" && export ACCUMULO_TSERVER_OPTS="${POLICY} -Xmx128m -Xms128m "
	test -z "$ACCUMULO_MASTER_OPTS" && export ACCUMULO_MASTER_OPTS="${POLICY} -Xmx128m -Xms128m"
	test -z "$ACCUMULO_MONITOR_OPTS" && export ACCUMULO_MONITOR_OPTS="${POLICY} -Xmx64m -Xms64m"
	test -z "$ACCUMULO_GC_OPTS" && export ACCUMULO_GC_OPTS="-Xmx64m -Xms64m"
	test -z "$ACCUMULO_SHELL_OPTS" && export ACCUMULO_SHELL_OPTS="-Xmx128m -Xms64m"
	test -z "$ACCUMULO_GENERAL_OPTS" && export ACCUMULO_GENERAL_OPTS="-XX:+UseConcMarkSweepGC -XX:CMSInitiatingOccupancyFraction=75 -Djava.net.preferIPv4Stack=true -XX:+CMSClassUnloadingEnabled"
	test -z "$ACCUMULO_OTHER_OPTS" && export ACCUMULO_OTHER_OPTS="-Xmx128m -Xms64m"
	test -z "${ACCUMULO_PID_DIR}" && export ACCUMULO_PID_DIR="${ACCUMULO_HOME}/run"

Therefore, it would be good if the tserver/statefulset.yaml had an option to take an abitrary number of environment variables from the values.yaml and set them.