Java 12 extensions update causing build failure

[theresa-m]

The last working build I have that is fixed in #3768 was at extensions commit "JCL - 8f2789f based on jdk-12+23)"

New errors:

/root/openj9-openjdk-jdk12/build/linux-x86_64-server-release/support/j9jcl_sources/java.base/share/classes/java/lang/System.java:133: error: cannot find symbol
                        VM.saveAndRemoveProperties(systemProperties);
                          ^
  symbol:   method saveAndRemoveProperties(Properties)
  location: class VM
/root/openj9-openjdk-jdk12/build/linux-x86_64-server-release/support/j9jcl_sources/java.base/share/classes/java/lang/System.java:301: error: incompatible types: Properties cannot be converted to Map<String,String>
        java.lang.VersionProps.init(systemProperties);