JBoss ON metric charts are missing their graph image when server's operating system is missing fonts used by Java AWT

Issue

• The Resource Measurement graphs are not display in the JBoss Operations Network (ON) UI.
• The pop-up window contains a placeholder for the graph, but the graph itself is not displayed.

• Errors like the following in the JBoss ON server log:

  java.lang.NoClassDefFoundError: Could not initialize class org..enterprise.gui.image.chart.ColumnChart
  

• Graphical Charts which displays the Metrics of different components identified by JBoss ON are not displayed.

• The statistics are getting displayed properly, however the image/graphic for the metric is not being rendered.