Use provided calling uid/pid for checking intercept-global-drag flag

- This particular path can not rely on ActivityTaskManagerService's
  enforceTaskPermission() call since that uses the binder calling
  uid/pid, which has been cleared prior to calling
  validateAddingWindowLw().

Bug: 428700812
Flag: EXEMPT bugfix
Test: atest DragDropControllerTests
Change-Id: I768dd22b9b107235cce60ffcc0e796d6a536b91d