Enter to touch mode by down or scroll event from any type of a device.

This CL reverts the touch mode behavior to that in N and prior.

Bug: 135752906
Bug: 147710276
Test: Mouse click causes entering to touch mode.
Test: ViewTest#testTouchMode
Change-Id: I9d6a8ad95fba524701df7d318732d553fce958f8
Merged-In: Id5fbb500eed279c66ed6817c2b7d001a5a68737a
(cherry picked from commit 391c123e9e)

core/java/android/view/ViewRootImpl.java

@@ -5699,9 +5699,9 @@ public final class ViewRootImpl implements ViewParent,
                 mTranslator.translateEventInScreenToAppWindow(event);
             }
 
-            // Enter touch mode if event is coming from a touch screen device.
+            // Enter touch mode on down or scroll from any type of a device.
             final int action = event.getAction();
-            if (event.isFromSource(InputDevice.SOURCE_TOUCHSCREEN)) {
+            if (action == MotionEvent.ACTION_DOWN || action == MotionEvent.ACTION_SCROLL) {
                 ensureTouchMode(true);
             }