Fix class initialization issue

We were getting an NPE because the superclass was
calling an overridden method on its constructor,
before the variable could be initialized.

Test: atest ScrimControllerTest
Fixes: 137665467
Fixes: 137878476
Change-Id: I8914eac86cac19d92a68a2d55d97dfcee4066ed3
(cherry picked from commit 1c72bc21514eb6b76f80cef68be1245fb5d4f423)