Use searchable="false" to suppress nonIndexables.

When possible, remove or simplify getNonIndexable() logic in fragments,
and use searchable="false" in xml to suppress index.

Change-Id: I5bdf5bc7d5494a64cdd9e230a51321a4b210af69
Fixes: 112608186
Test: robotest and manual search

src/com/android/settings/inputmethod/VirtualKeyboardFragment.java

@@ -27,6 +27,8 @@ import android.provider.SearchIndexableResource;
 import android.view.inputmethod.InputMethodInfo;
 import android.view.inputmethod.InputMethodManager;
 
+import androidx.preference.Preference;
+
 import com.android.internal.logging.nano.MetricsProto.MetricsEvent;
 import com.android.internal.util.Preconditions;
 import com.android.settings.R;
@@ -42,8 +44,6 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
-import androidx.preference.Preference;
-
 @SearchIndexable
 public final class VirtualKeyboardFragment extends SettingsPreferenceFragment implements Indexable {
 
@@ -130,12 +130,5 @@ public final class VirtualKeyboardFragment extends SettingsPreferenceFragment im
                     sir.xmlResId = R.xml.virtual_keyboard_settings;
                     return Arrays.asList(sir);
                 }
-
-                @Override
-                public List<String> getNonIndexableKeys(Context context) {
-                    final List<String> keys = super.getNonIndexableKeys(context);
-                    keys.add("add_virtual_keyboard_screen");
-                    return keys;
-                }
             };
 }