Java 11 version number format change

This rule detects the System.getProperty method call on the java.version property key. In Java releases prior to Java 9, any java version number matched the naming convention 1.x.y_z where the major version number is declared as x. For example, a Java 8 version could be 1.8.0_210. Starting at Java 9, all Java version numbers follow the new naming convention of x.y.z where x declares the major version number. An example of a Java 11 version would be 11.0.4. This format change could cause issues if code was written depending on the prior naming convention.