Avoid handle the pointer-down-outside if the input target is invisible

The input target is updated by a message posted from InputManager.
It is possible that the pointer-down-outside event is ready to execute
after the delay, but the focused input target is not yet updated.

Bug: 377631863
Test: Enable A11Y on Settings and follow the steps on the bug
Flag: EXEMPT bugfix
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:d8f80e16ca1c4c5f37638d117ca674ae997a73ec)
Merged-In: I02a22177ff1cb62d7cb701fdad0c02fd62b94f5d
Change-Id: I02a22177ff1cb62d7cb701fdad0c02fd62b94f5d