Clear swipe region cache on nav mode switch

Fixes: 154955192, 150958400
Test: Switched from gesture nav to 3 button,
was no longer able to swipe up

Change-Id: Icc7b27eb7bd1eb5ddf25d7e7c3464a77a3a88f24

quickstep/src/com/android/quickstep/OrientationTouchTransformer.java

@@ -99,6 +99,10 @@ class OrientationTouchTransformer {
             return;
         }
         this.mMode = newMode;
+        // Swipe touch regions are independent of nav mode, so we have to clear them explicitly
+        // here to avoid, for ex, a nav region for 2-button rotation 0 being used for 3-button mode
+        // It tries to cache and reuse swipe regions whenever possible based only on rotation
+        mSwipeTouchRegions.clear();
         resetSwipeRegions(info);
     }