How does Firebase Analytics define a “user” (for purposes of Audience)?
问题 I've been told that, "Once a user is in an audience, they will forever be in that audience". I'm curious how long is "forever," in the context of a user? For instance, if a user changes phones, or uninstalls the app and then re-installs later, does the user persist across those transitions, or is each of those a separate user? And if I have multiple apps in one Firebase project, does the user appear in the same audience in all apps within that project? What does Firebase Analytics consider to