Export jar-args.sh script to make

Export jar-args.sh in JAR_ARGS so that make doesn't have to
duplicate the sed scripts.

Test: m -j checkbuild
Bug: 64634025
Change-Id: Ia5d0a303f23b32b8ff672fc882d51d5e99316ffa
diff --git a/java/config/makevars.go b/java/config/makevars.go
index ec0d939..ac02782 100644
--- a/java/config/makevars.go
+++ b/java/config/makevars.go
@@ -34,6 +34,7 @@
 	ctx.Strict("JAVA", "${JavaCmd}")
 	ctx.Strict("JAVAC", "${JavacCmd}")
 	ctx.Strict("JAR", "${JarCmd}")
+	ctx.Strict("JAR_ARGS", "${JarArgsCmd}")
 	ctx.Strict("JAVADOC", "${JavadocCmd}")
 	ctx.Strict("COMMON_JDK_FLAGS", "${CommonJdkFlags}")
 }