Reporting server v2 CEL environment does not contain v2 event group descriptor and list event groups with filter option fail (v0.4.2)

[BaibaSku]

Describe the bug
(v0.4.2) When calling list event groups with filter on reporting server v2 and using fields, which are relevant to event group (v2) only (cmms_data_provider field as an example), the request fails, with following error message:

INVALID_ARGUMENT: filter is not a valid CEL expression: ERROR: :1:1: undeclared reference to 'cmms_data_provider' (in container 'wfa.measurement.reporting.v1alpha.EventGroup')\n | cmms_data_provider == 'dataProviders/a0tmyormbgQ'

Steps to reproduce

1. Call list event groups on reporting server v2 by using cel expression, which contains v2 Event group field. Example:cmms_data_provider == 'dataProviders/a0tmyormbgQ'

Component(s) affected
Reporting Server

Version
0.4.2

[mariolamassaavedra]

This error seems to be cause due to the CEL Env Provider not importing the Reporting Server v2 definition of the event groups object and only referencing v1

[SanjayVas]

@tristanvuong2021 can you take a look at this? We probably need separate CelEnvProvider impls for v1 and v2, given that it depends on an API message.