Report toolType on handwriting start

We update last click toolType onStartInput. However, when stylus is used
to start handwriting, it is a click euqivalent operation for which
ViewRootImpl never receives ACTION_UP event.
For a successful intiation, we should update toolType so that next
startInput has that available in EditorInfo.

Bug: 283701472
Test: atest StylusHandwritingTest
Change-Id: Id5f08e43c24cd42b416456a6c14fed0c130554c9