Use javaPathHelper

Index: Ghidra/RuntimeScripts/Linux/support/launch.sh
--- Ghidra/RuntimeScripts/Linux/support/launch.sh.orig
+++ Ghidra/RuntimeScripts/Linux/support/launch.sh
@@ -126,7 +126,7 @@ else
 fi
 
 # Identify java command from either JAVA_HOME or PATH, try PATH first
-JAVA_CMD=
+JAVA_CMD="$(javaPathHelper -c ghidra)"
 if [ -x "$(command -v java)" ] ; then
 	JAVA_CMD=java
 elif [ -n "${JAVA_HOME}" ] ; then
