Fix DefaultImeVisibilityApplierTest on auto surfaces

Make mUserId private in InputMethodBindingController so it can be
properly mocked in tests.

Fix: 350205242
Test: atest FrameworksInputMethodSystemServerTests:com.android.server.inputmethod.DefaultImeVisibilityApplierTest
Test: atest FrameworksInputMethodSystemServerTests:com.android.server.inputmethod.UserDataRepositoryTest
Flag: EXEMPT bug fix
Change-Id: I5e3f27411207355da7021213e28144c23670c062
5 files changed