Use InputManagerInternal to report last toolType

In the past we've explored various ways to pipe last used tooltype,
however most effective way is to ask InputManager. This makes sure it is
always up-to-date and isn't restricted to a ViewRoot.

Fix: 336615195
Test: atest StylusHandwritingTest

Change-Id: I17b9d7d13e2fa265c0f9b04f1cf7193a1ce86638