Fix issue with home activity started with standard activity type

- Specifically in the case where we have a merged Launcher+Recents activity
  and there is no default home activity set, allow the recents button
  handler to launch the merged home activity (in Overview mode) without
  showing a disambig dialog (by having the component set in the home intent)

Bug: 79878243
Test: Disable swipe up (enable 3 button nav), launch an app, reinstall
      launcher in the background to remove the home stack, tap the recents
      button and ensure we launch home with ACTIVITY_TYPE_HOME.

Change-Id: I4d114b7f474390dd6fe9bdadc58a399a2daf1b81

services/core/java/com/android/server/am/ActivityRecord.java

@@ -1077,6 +1077,11 @@ final class ActivityRecord extends ConfigurationContainer implements AppWindowCo
             // System process can launch home activity.
             return true;
         }
+        // Allow the recents component to launch the home activity.
+        final RecentTasks recentTasks = mStackSupervisor.mService.getRecentTasks();
+        if (recentTasks != null && recentTasks.isCallerRecents(uid)) {
+            return true;
+        }
         // Resolver activity can launch home activity.
         return sourceRecord != null && sourceRecord.isResolverActivity();
     }