Adaptive scribe bounds: InputMethodService apis 2/n

Introduce InputMethodService API that allow IME to
adapt the scribe touchable area during a session.

Bug: 350047836
Flag: android.view.inputmethod.adaptive_handwriting_bounds
Test: atest CtsInputMethodTestCases StylusHandwritingTest
API-Coverage-Bug: 350047836

Change-Id: I0452a5469b12f0c27b0859029f9185f4c3e810d5