[Panlingual] Implement entries of Panlingual in settings UI part.

- Path 1 : System -> Language & Input -> App Languages -> per app
 language
 - path 2 : System -> Apps -> App Info -> per app language
 Video: https://screencast.googleplex.com/cast/NjUyNTUzMDY0MTc5MzAyNHxjNTg2MzMwYS0yOA

Bug: 206854105
Test: local test pass
Test: atest pass

Change-Id: Ic06fa4f0c6ec68680eb828032b6e3f479b412dc4

src/com/android/settings/applications/appinfo/AppLocalePreferenceController.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.applications.appinfo;
+
+import android.content.Context;
+import android.util.FeatureFlagUtils;
+
+import com.android.settings.SettingsPreferenceFragment;
+
+/**
+ * A controller to update current locale information of application.
+ */
+public class AppLocalePreferenceController extends AppInfoPreferenceControllerBase {
+    public AppLocalePreferenceController(Context context, String key) {
+        super(context, key);
+    }
+
+    @Override
+    public int getAvailabilityStatus() {
+        return FeatureFlagUtils
+                .isEnabled(mContext, FeatureFlagUtils.SETTINGS_APP_LANGUAGE_SELECTION)
+                ? AVAILABLE : CONDITIONALLY_UNAVAILABLE;
+    }
+
+    @Override
+    protected Class<? extends SettingsPreferenceFragment> getDetailFragmentClass() {
+        return AppLocaleDetails.class;
+    }
+
+    @Override
+    public CharSequence getSummary() {
+        return AppLocaleDetails.getSummary(mContext, mParent.getAppEntry().info.packageName);
+    }
+}