Handle non-initalized InkWindow

With [1] we changed the lifecycle of InkWindow to be short lived and
missed certain cases.

This also fixes CTS testStylusSession_fingerTriggersNavbarGestures

Bug: 243571274
Test: atest StylusHandwritingTest

[1]: Icd3eea91fe144cff7100d3ecf19191c064c0d196

Change-Id: I1593ff10a5520aadb5ed86a4a09f2405ee65c321