Make IMMS#calledWithValidTokenLocked() multi-user aware

With this CL,

  InputMethodManagerService##calledWithValidTokenLocked()

starts taking userId into account.

For single-user IME mode, there must be no user observable behavior
change. for multi-user IME mode, which is

  IMMS#mExperimentalConcurrentMultiUserModeEnabled

enabled environement, this CL enables that IPC-based requests from IME
processes that are associated with visible background users will start
passing the virification.

Bug: 305849394
Test: presubmit
Flag: android.view.inputmethod.concurrent_input_methods
Change-Id: Iddf5dc9a4b866c84a930da9da3d0fd4430063b5c