CursorInputMapper: migrate remaining tests

Change I0f0307dc57edcc62d0ce24b15bf0d9e8b8b915c6 left a few tests using
the old InputMapperTest (instead of the new InputMapperUnitTest),
because they needed a fake InputDeviceContext creating (or looked like
they needed it; some turned out to be simpler to migrate). This change
moves them over.

Bug: 283812079
Test: atest inputflinger_tests
Change-Id: I18c82c7823f0739b62dba06f4e550069b3d0130e