Track change to applyBlur function signature in tests

The new argument is optional but Mockito requires that all of the
arguments are filled out for capture/verification.

Test: atest DreamOverlayContainerViewControllerTest
Bug: 391463550
Flag: com.android.systemui.spatial_model_pushback_in_shader
Change-Id: I1cf72529ba8ae0d789677928c96fd46b18dea30f