Restart SysUI before starting the suite

This CL enforces the SystemUI process to be restarted before running the
ConnectedDisplayCujSmokeTests to ensure it’s in a clean state.
Otherwise, prior tests may leave it dirty.

Flag: EXEMPT - test stabilization
Bug: 442453305
Bug: 442453913
Bug: 442454448
Bug: 442453123
Bug: 442453799
Test: atest WMShellSmokeTestsDesktopMode
Change-Id: I7bc7dbb1b8ebd8d6d865018b2fe855ccf4446095