Subset of services experiment

[bwateratmsft]

Fixes #2646. This adds a new option to launch a subset of services directly; basically it is equivalent to appending ${serviceList} to the end of your compose command. This is gated by an experiment.

[karolz-ms]

Glad to see that it is relatively easy to set up such experiment! ☺️

[bwateratmsft]

@karolz-ms @BigMorty @ucheNkadiCode @philliphoff -- as an alternative, we could keep just one command and show the service checklist every time; we can do this as an experiment so we're not bothering everybody. We can measure success if people are actually using it; we capture the numerator (number of services selected) and denominator (total number of services). If selected < total, it stands to reason they did make use of the feature; otherwise not. If we saw, for example, that 95% were not using it, then combining commands is probably not the way to go. But if, say, 50% were using it--maybe one command is right.

Thoughts? In short, the options are:

1. Separate "choose services" command, show the "choose services" command to the treatment group
   • Success: using this command
   • Success: the number of services selected being less than total number of services
   • Failure: people frequently start but cancel the "choose services" command
2. One single command, show the subset picker to the treatment group
   • Success: the number of services selected is frequently less than the total number of services
   • Failure: very few people use the checklist; it's just a popup in the way

[BigMorty]

Interesting idea @bwateratmsft. I could go either way, but I lean towards having the separate menu/command.

[bwateratmsft]

Interesting idea @bwateratmsft. I could go either way, but I lean towards having the separate menu/command.

That would be my inclination as well.