Remove lock delay on exiting edit mode activity

I no longer see a flash of the lock screen with the delay removed. The
delay is also causing a few other issues.

Bug: 346433377
Fix: 346433377
Bug: 344627152
Fix: 344627152
Bug: 325108777
Test: manually verified CUJs, see b/325108777 for video of current
      state
Flag: com.android.systemui.communal_hub
Change-Id: Id5c513a63d6607474357aa4bd5e32578064968ef