(Once more) fix minimum height of mode name edit box for a11y

We had fixed this before and then regressed when moving to TextInputLayout, so added a proper test this time.

Fixes: 380207192
Test: atest ZenModeEditNamePreferenceControllerTest
Flag: android.app.modes_ui
Change-Id: Ic25b0a5a6997e7b3bb26bf26ed7e8e92654a1c11