SF: Fix libcompositionengine_test Expectations around display IDs

https://googleplex-android-review.git.corp.google.com/c/platform/frameworks/native/+/31654940
seems to have introduced a regression in libcompositionengine_test
around CompositionEngineTest SetUp().

This CL fixes this issue.

Flag: EXEMPT bugfix
Bug: 403479642
Test: libcompositionengine_test
Change-Id: Ic8c05895f084faaffb2d228d2630ce995df572bd