Fix drag and drop access wrong pointer id

If the touched window didn't support split, it won't track the
pointerIds. When the drag and drop started, it would rely on the
pointerIds to check current touch state and store the initial drag
pointer id but it would always be 0.

This CL will let pointerIds could track all down pointers when touched
windows received down or pointer down, so it could access the right
pointer id from current touch state.

Test: atest inputflinger_tests CrossAppDragAndDropTests
Bug: 237233207
Change-Id: Ia5d91814a2aca56095c29b029e35e66cd669bce9
diff --git a/services/inputflinger/dispatcher/TouchedWindow.h b/services/inputflinger/dispatcher/TouchedWindow.h
index 0962d0c..a7839db 100644
--- a/services/inputflinger/dispatcher/TouchedWindow.h
+++ b/services/inputflinger/dispatcher/TouchedWindow.h
@@ -29,7 +29,7 @@
 struct TouchedWindow {
     sp<gui::WindowInfoHandle> windowHandle;
     int32_t targetFlags;
-    BitSet32 pointerIds; // zero unless target flag FLAG_SPLIT is set
+    BitSet32 pointerIds;
     bool isPilferingPointers = false;
     // Time at which the first action down occurred on this window.
     // NOTE: This is not initialized in case of HOVER entry/exit and DISPATCH_AS_OUTSIDE scenario.