[SPARK-3068]remove MaxPermSize option for jvm 1.8

In JVM 1.8.0, MaxPermSize is no longer supported.
In spark `stderr` output, there would be a line of

    Java HotSpot(TM) 64-Bit Server VM warning: ignoring option MaxPermSize=128m; support was removed in 8.0

We are now using the java which the worker started with to run executor, so to judge perm size setting we should refer to the specific java version.