Add user.roles to the intake

Currently, if I call this:

set_context({"username": "my_username"}, "user")

it does nothing. I'm told that it does nothing because the APM Server intake isn't looking for this field. Maybe add all of the fields listed on this page https://www.elastic.co/guide/en/apm/server/current/exported-fields-ecs.html#_user

I'm using v 6.2.3. This thread has some more information https://discuss.elastic.co/t/in-the-python-elastic-apm-v-6-2-3-library-how-do-i-set-the-user-roles-field/298982