Provide Eclipse OpenJ9 as alternative Java runtime for OW java action

[Param-S]

Eclipse OpenJ9 is a opensource Java runtime well optimised for the cloud native applications. AdoptOpenJDK community has packaged the Eclipse OpenJ9 runtime with OpenJDK classes.

It allows the Java action developers to choose between the Hotspot JVM and Eclipse OpenJ9 JVM for running java actions.

[Param-S]

PR #24 created to enable AdoptOpenJDK Eclipse OpenJ9 runtime for OW Java actions.

[kameshsampath]

@Param-S - we already have one PR #18 running to modify the runtime, instead of separate runtime all together why cant we work to have this merged with other ?

@jthomas @csantanapr @rabbah @gorkem thoughts ???

[csantanapr]

@kameshsampath I prefer to replace the runtime with opnejdk//ubuntu PR #24 and not replace with centos based one from PR #18

[kameshsampath]

@csantanapr, I am fine. As discussed we should java-ubuntu:8 and java-centos:8 kind of distros.
A question here is these are JDK 9 ones, are we planning to have AdoptOpenJDK 8 as well ?

[csantanapr]

This PR is for java 8 is my understanding

[Param-S]

Yes, this PR is for Java 8. Using the community build AdoptOpenJDK.

[csantanapr]

Closed by #24