Don't show autofill settings if not enabled

The non-indexable keys of language-and-input on my angler are:
  game_controller_settings_category, gesture_assist,
  gesture_double_tap_screen, default_autofill

Fixes: 35956220
Test: Disabled auto-fill and looked at settings: did not find
      autofill button and could not find auto-fill in search
      Settings robolectric test
Merged-In: I0923e707422d1b1de5153a63fa3a5fe4773c055d
Change-Id: I0923e707422d1b1de5153a63fa3a5fe4773c055d

tests/robotests/src/com/android/settings/language/LanguageAndInputSettingsTest.java

@@ -31,6 +31,7 @@ import android.content.pm.PackageManager;
 import android.hardware.input.InputManager;
 import android.os.UserManager;
 import android.provider.Settings;
+import android.view.autofill.AutofillManager;
 import android.view.inputmethod.InputMethodInfo;
 import android.view.inputmethod.InputMethodManager;
 import android.view.textservice.TextServicesManager;
@@ -72,6 +73,8 @@ public class LanguageAndInputSettingsTest {
     private DevicePolicyManager mDpm;
     @Mock
     private InputMethodManager mInputMethodManager;
+    @Mock
+    private AutofillManager mAutofillManager;
     private TestFragment mFragment;
 
     @Before
@@ -84,6 +87,7 @@ public class LanguageAndInputSettingsTest {
                 .thenReturn(mock(TextServicesManager.class));
         when(mContext.getSystemService(Context.DEVICE_POLICY_SERVICE)).thenReturn(mDpm);
         when(mContext.getSystemService(Context.INPUT_METHOD_SERVICE)).thenReturn(mImm);
+        when(mContext.getSystemService(AutofillManager.class)).thenReturn(mAutofillManager);
         mFragment = new TestFragment(mContext);
     }