Fix TrigUpgradeTest unit test emu_step_processing
As explained in !29940 (comment 3152974) the fix was to simply revert 7347e43a. While looking at this test, I also fixed some python imports flagged by flake8.
Closes ATR-20849
As explained in !29940 (comment 3152974) the fix was to simply revert 7347e43a. While looking at this test, I also fixed some python imports flagged by flake8.
Closes ATR-20849