Don't eagerly parse runtime options

[lunaris]

Parsing runtime options eagerly is likely at risk of triggering an issue like pulumi/pulumi-dotnet#443, but for Java. Even if it isn't, we should push the parsing of options "in" so that it's done when needed, as opposed to at boot-up (which is deprecated behaviour anyway since in the future the engine won't even send the runtime options at startup). We likely need something similar to pulumi/pulumi-dotnet#451 (.Net) or pulumi/pulumi-yaml#709 (YAML)