Mock out one more overload of Context#registerReceiver()

This is a preparation before making

  InputMethodManagerService#mImeDrawsImeNavBarRes

multi-user ready.

Instantiating InputMethodManagerService results in invoking

  SystemLocaleWrapper#onStart(),

which internally registers a BroadcastReceiver.  All the tests based
on InputMethodManagerServiceTestBase are now failing to unregister
such receivers.

Let's make it no-op by mocking

  Context#registerReceiver(
      BroadcastReceiver, IntentFilter, String, Handler)

for now.

Bug: 345519864
Test: atest FrameworksInputMethodSystemServerTests
Flag: TEST_ONLY
Change-Id: Ia457d631eda0f04a7acdd92315b896a97aa4fcb1