Refactor InputWindowHandle JNI code

* Remove unnecessary NativeInputWindowHandle wrapper class
* Combine getting and updating WindowInfoHandle into a single function
* Remove unnecessary copying of gui::WindowInfoHandle in android_view_InputWindowHandle_fromWindowInfo and Transaction::setInputWindowInfo

Bug: 294381558
Flag: EXEMPT refactor
Test: presubmits
Change-Id: Iaacbc1e5a39446483ea0d4aa38f5de1c33534160