Import is_service_enabled from module

An additional step for H302, and needed here to make mocking
is_service_enabled across modules more consistent and easier
(e.g. mocking only one signature as opposed to both
api.base.is_service_enabled and quotas.is_service_enabled).

Partial-Bug: #1109140

Change-Id: Ie6cec3138de6f2fc57b68e90db45f53bb94ab87d
Merge "Import is_service_enabled from module"