Update Java settings and JDK requirement in Java containers

[testforstephen]

Fixes #1444

• Remove "java.home" setting from devcontainer.json since it's deprecated in the latest Java extension.
• Remove JDK 11 from Java 8 container, since VS Code Java extension has embedded a JRE 17 in extension itself, no requirement for JDK 11 any more.

[Chuxel]

LGTM! Also adding Brigit and Josh to the review since they're starting to drive dev containers (partly tied to plans related to containers.dev).

I guess one question is whether we should fully drop java-8 and just add that to the java definition. Are there any differences anymore?

@bamurtaugh @joshspicer Removing JDK 11 from the JDK8 image makes sense and is great, but this would be a breaking change for existing java-8 devcontainer.json files. So I think we should probably do a major version bump in definition-manifest.json for the release and tweak any related Dockerfiles to be java:1-<JDK version> instead of java:0-<JDK version>

@joshspicer Note that the related dev container future here could be tweaked to no longer install JDK11 automatically if JDK8 is selected.

We can also tweak https://github.com/microsoft/vscode-remote-try-java

[testforstephen]

I guess one question is whether we should fully drop java-8 and just add that to the java definition. Are there any differences anymore?

This is a good question. It makes sense to merge java-8 to the general java definition. Currently one problem is we're using Microsoft Build of OpenJDK for Java 11 and Java 17, but use Eclipse Tem for Java 8 because Microsoft doesn't provide Java 8 build.

To install JDKs from different sources in one Dockerfile, we need to tweak the installation script a bit more. I'd take this as a follow-up of this PR.

[bamurtaugh]

Thanks for the tag, @Chuxel, and for making this change, @testforstephen!

I think we should probably do a major version bump in definition-manifest.json for the release and tweak any related Dockerfiles to be java:1- instead of java:0-

This makes sense - @testforstephen would you be able to make this change in this PR too?

We can also tweak https://github.com/microsoft/vscode-remote-try-java

I can open a PR there to update that one.

[testforstephen]

I think we should probably do a major version bump in definition-manifest.json for the release and tweak any related Dockerfiles to be java:1- instead of java:0-

@bamurtaugh done, I have bumped java-8 image to 1.0.0.

[bamurtaugh]

Thanks @testforstephen! If there are no other thoughts or concerns @joshspicer @Chuxel, I'll merge this update.

I also opened microsoft/vscode-remote-try-java#39 to update the Java try sample and tagged @testforstephen for review.

[joshspicer]

LGTM too!