Improve quick switch from home to taskbar

- Add LauncherState#isTaskbarAlignedWithHotseat() which defaults to !isTaskbarStashed(), but is always false for quick switch from home
- Replaced FLAG_TRANSITION_STATE_START_STASHED and FLAG_TRANSITION_STATE_COMMITTED_STASHED with FLAG_STATE_TRANSITION_RUNNING and a reference to mLauncherState. STATE_START is equivalent to TRANSITION_RUNNING changing to true, and STATE_COMMITTED is equivalent to TRANSITION_RUNNING changing to false. Then can get details from the state such as whether taskbar is stashed and icon alignment from mLauncherState

Test: quick switch from home, both with taskbar stashed in apps and not
Fixes: 194728611
Bug: 204657916
Change-Id: I6cf84ec73a4036e14cc7268667c6f62100884c27

quickstep/src/com/android/quickstep/views/RecentsView.java

@@ -629,7 +629,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
      * this doesn't get adjusted to reflect the new child count after the taskView is dismissed/
      * removed from recentsView
      */
-    private int mSplitHiddenTaskViewIndex;
+    private int mSplitHiddenTaskViewIndex = -1;
     @Nullable
     private FloatingTaskView mFirstFloatingTaskView;
     @Nullable
@@ -3959,6 +3959,9 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
 
     /** TODO(b/181707736) More gracefully handle exiting split selection state */
     private void resetFromSplitSelectionState() {
+        if (mSplitHiddenTaskViewIndex == -1) {
+            return;
+        }
         if (!mActivity.getDeviceProfile().overviewShowAsGrid) {
             int pageToSnapTo = mCurrentPage;
             if (mSplitHiddenTaskViewIndex <= pageToSnapTo) {