Set StateManager to BackgroundAppState if end gesture is NEW_TASK

* QUICK_SWITCH_FROM_HOME was incorrectly used as that LauncherState
is only meant for quickswitching for the most recent task from
workspace

Bug: 265734073
Test: Tested quickswitch with fullscreen and splitscreen tasks
Change-Id: Ia81152927f57203cf6adb90254675bcf82a2e836
diff --git a/quickstep/src/com/android/quickstep/LauncherActivityInterface.java b/quickstep/src/com/android/quickstep/LauncherActivityInterface.java
index 89e8f51..7f2886c 100644
--- a/quickstep/src/com/android/quickstep/LauncherActivityInterface.java
+++ b/quickstep/src/com/android/quickstep/LauncherActivityInterface.java
@@ -346,7 +346,6 @@
             case RECENTS:
                 return OVERVIEW;
             case NEW_TASK:
-                return QUICK_SWITCH_FROM_HOME;
             case LAST_TASK:
                 return BACKGROUND_APP;
             case HOME: