[SPARK-3425] do not set MaxPermSize for OpenJDK 1.8

nice catch. i had tried parens, but they don't work. it'll have to be a .*

````
$ java -version
openjdk version "1.8.0_11"
OpenJDK Runtime Environment (build 1.8.0_11-b12)
OpenJDK 64-Bit Server VM (build 25.11-b02, mixed mode)
$ echo 'openjdk version "1.8.0_11"' | sed 's/java\|openjdk version "\(.*\)\.\(.*\)\..*"/\1\2/; 1q'
18
$ echo 'java version "1.8.0_11"' | sed 's/java\|openjdk version "\(.*\)\.\(.*\)\..*"/\1\2/; 1q'   
 version "1.8.0_11"
$ echo 'java version "1.8.0_11"' | sed 's/(java\|openjdk) version "\(.*\)\.\(.*\)\..*"/\1\2/; 1q'
java version "1.8.0_11"
$ echo 'openjdk version "1.8.0_11"' | sed 's/(java\|openjdk) version "\(.*\)\.\(.*\)\..*"/\1\2/; 1q'
openjdk version "1.8.0_11"
$ echo 'java version "1.8.0_11"' | sed 's/.* version "\(.*\)\.\(.*\)\..*"/\1\2/; 1q'
18
$ echo 'openjdk version "1.8.0_11"' | sed 's/.* version "\(.*\)\.\(.*\)\..*"/\1\2/; 1q'
18
````