add substitude for java opts, too.

add substitute args for while forking java process. 
So we can set extra java opst like this:

```
-XX:+PrintGCDetails -XX:+PrintGCDateStamps -verbose:gc -Xloggc:/tmp/spark.executor.{{HOSTNAME}}.{{APP_ID}}.{{EXCUTOR_ID}}.gc.log
```
to avoid gc log to be overwriten
I think I agree with this. I'm not sure the function every correctly replaced these placeholders within a larger string.