Return to dream from occlusion.

This changelist tracks the dream state when the lockscreen is occluded
and then returns to that state on unocclusion.

Test: atest KeyguardTransitionScenariosTest#dreamingToOccludedToDreaming
Test: atest CommunalDreamStartableTest#CommunalDreamStartableTest#restartDreamingWhenTransitioningFromDreamingToOccludedToDreaming
Fixes: 338051457
Flag: ACONFIG com.android.systemui.restart_dream_on_unocclude disabled
Change-Id: If075685b466aa4a4ccfd77a757a7d715ccf5d3e3
diff --git a/packages/SystemUI/aconfig/systemui.aconfig b/packages/SystemUI/aconfig/systemui.aconfig
index 80398cd..df44076 100644
--- a/packages/SystemUI/aconfig/systemui.aconfig
+++ b/packages/SystemUI/aconfig/systemui.aconfig
@@ -857,6 +857,16 @@
 }
 
 flag {
+   name: "restart_dream_on_unocclude"
+   namespace: "systemui"
+   description: "re-enters dreaming upon unocclude when dreaming when originally occluding"
+   bug: "338051457"
+   metadata {
+     purpose: PURPOSE_BUGFIX
+   }
+}
+
+flag {
   name: "communal_bouncer_do_not_modify_plugin_open"
   namespace: "systemui"
   description: "do not modify notification shade when handling bouncer expansion."