Fix QSB becoming invisible

This could not be reproduced until I removed a line that wouldn't call
onAssistantVisiblityChanged if the argument was the same value as the
argument as the previous call.

After that, the bug became readily reproducible. I traced through
Launcher till I found that FallbackActivityControllerHelper
.onAssistantVisibilityChanged was being called while the screen was
locked, proving that onAssistantVisiblityChanged was _not_ reaching
launcher.

Test: Verify bug no longer reproduces.
Bug: 134981174
Bug: 135247753
Bug: 135572849
Bug: 135733393
Bug: 136386749
Bug: 136776987
Bug: 137534772
Bug: 137764419

Change-Id: Ib5e8df3b5030a77c5df351a1fcd993db6bd602fc
diff --git a/quickstep/recents_ui_overrides/src/com/android/quickstep/FallbackActivityControllerHelper.java b/quickstep/recents_ui_overrides/src/com/android/quickstep/FallbackActivityControllerHelper.java
index c43155b..8c5a788 100644
--- a/quickstep/recents_ui_overrides/src/com/android/quickstep/FallbackActivityControllerHelper.java
+++ b/quickstep/recents_ui_overrides/src/com/android/quickstep/FallbackActivityControllerHelper.java
@@ -80,7 +80,9 @@
 
     @Override
     public void onAssistantVisibilityChanged(float visibility) {
-        // TODO:
+        // This class becomes active when the screen is locked.
+        // Rather than having it handle assistant visibility changes, the assistant visibility is
+        // set to zero prior to this class becoming active.
     }
 
     @NonNull
diff --git a/quickstep/src/com/android/quickstep/OverviewComponentObserver.java b/quickstep/src/com/android/quickstep/OverviewComponentObserver.java
index 4a2ed3a..88a4eb6 100644
--- a/quickstep/src/com/android/quickstep/OverviewComponentObserver.java
+++ b/quickstep/src/com/android/quickstep/OverviewComponentObserver.java
@@ -116,6 +116,14 @@
                 .getHomeActivities(new ArrayList<>());
 
         mIsDefaultHome = Objects.equals(mMyHomeIntent.getComponent(), defaultHome);
+
+        // Set assistant visibility to 0 from launcher's perspective, ensures any elements that
+        // launcher made invisible become visible again before the new activity control helper
+        // becomes active.
+        if (mActivityControlHelper != null) {
+            mActivityControlHelper.onAssistantVisibilityChanged(0.f);
+        }
+
         if ((mSystemUiStateFlags & SYSUI_STATE_HOME_DISABLED) == 0
                 && (defaultHome == null || mIsDefaultHome)) {
             // User default home is same as out home app. Use Overview integrated in Launcher.
@@ -131,6 +139,7 @@
             }
         } else {
             // The default home app is a different launcher. Use the fallback Overview instead.
+
             mActivityControlHelper = new FallbackActivityControllerHelper();
             mIsHomeAndOverviewSame = false;
             mOverviewIntent = mFallbackIntent;