Removes checks that are not relevant to the particular tests. The checks
create dependencies on the CallTest base class. This prepares for
further refactoring in CallTest.
Bug: webrtc:9510
Change-Id: Ie6b0093a8fcb8a152ca58f421727c4b085b60a87
Reviewed-on: https://webrtc-review.googlesource.com/87845
Reviewed-by: Stefan Holmer <stefan@webrtc.org>
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23930}