GestureConverter_test: disable pointer controller with choreographer

These tests were unrealistic in that when the pointer choreographer flag
was enabled, the FakePointerController would continue keeping track of
the pointer position, even though the real PointerControllers would not
(see change I475f3286c83b90e161e186e62c2842e539434603). Modify the fake
so that it can be disabled, too.

Bug: 245989146
Test: atest inputflinger_tests:GestureConverterTest \
            inputflinger_tests:GestureConverterTestWithChoreographer
Change-Id: I7c7dd535804ca1552fb731e6da9fd148c047791b