Do not allow swipe to hub from dream or lockscreen

Additionally, change the following transitions to simple fade:
- launch hub by quick affordance on lockscreen
- launch hub by tapping dream
- launch hub from dream when dream crashes
- go back to dream from hub after timeout

Test: atest DreamOverlayServiceTest
Test: verified cannot swipe from dream or lockscreen to hub
Test: verified cannot swipe from hub to dream or lockscreen
Bug: 378173758
Flag: com.android.systemui.communal_hub_on_mobile
Flag: com.android.systemui.glanceable_hub_shortcut_button

Change-Id: Ie369127c22407bd691b6f00a01369b563bdd3ca9