PR B of three. Same chart as 1.0.0+upjava8, published for the second Java
line: appVersion selects the image tag, so the JVM is fixed per published
chart version.
minecraft.version moves with it (1.12.2 -> 1.20.1), because a Minecraft
version only runs on a matching JVM: Java 8 goes up to 1.16.5, 1.18-1.20.4
need Java 17. Since 1.0.0 this default is no longer overridden in the CI
values, so the install-test boots exactly this version and a mismatched
default would fail CI instead of passing on a CI-only override.
jklein
766058258a