rally.js must have the user's rally id in order to send glean.js pings

[hamilton]

This was caught by @Dexterp37. We will need the user's rally id in order to send the glean ping. One way we can make sure we have it is to store the rally id is for ._checkForRallyCore to return the rally id, which would be stored in the instance (something like instance.rallyID. This would enable us to pass it into the glean submission.

This requires us to:

• publish a new version of rally.js
• update the core add-on to pass the id
• update RS01 (our testbed for glean.js) to use the new version of rally.js

[Dexterp37]

Note: because this is defined as a 'user' lifetime metric, it only needs to be set once (it can be set multiple times too, but it's not required)