[Material Next] Update accessibility tool footer style

1. Implement API extends Material Next FooterBarPreference and support Accessibility API for icons
2. Apply solutions to accessibility tools and framework tools in
accessibility settings page.
3. Apply DashboardFragment for Caption preference for xml parser

Bug: 185973304
Test: make RunSettingsRoboTests -j52
Change-Id: I6b80bc80190d6666e3fbcd462442a9f2c0e60bba

tests/robotests/src/com/android/settings/accessibility/CaptionFooterPreferenceControllerTest.java

@@ -0,0 +1,65 @@
+/*
+ * 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.accessibility;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import android.content.Context;
+
+import androidx.preference.PreferenceManager;
+import androidx.preference.PreferenceScreen;
+import androidx.test.core.app.ApplicationProvider;
+
+import com.android.settings.R;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+
+/** Tests for {@link CaptionFooterPreferenceController}. */
+@RunWith(RobolectricTestRunner.class)
+public class CaptionFooterPreferenceControllerTest {
+
+    private static final String TEST_KEY = "test_key";
+    private final Context mContext = ApplicationProvider.getApplicationContext();
+    private PreferenceScreen mScreen;
+    private CaptionFooterPreferenceController mController;
+
+    @Before
+    public void setUp() {
+        final PreferenceManager preferenceManager = new PreferenceManager(mContext);
+        mScreen = preferenceManager.createPreferenceScreen(mContext);
+        final AccessibilityFooterPreference footerPreference =
+                new AccessibilityFooterPreference(mContext);
+        footerPreference.setKey(TEST_KEY);
+        mScreen.addPreference(footerPreference);
+        mController = new CaptionFooterPreferenceController(mContext, TEST_KEY);
+    }
+
+    @Test
+    public void onPreferenceChange_shouldSetCorrectIconContentDescription() {
+        mController.displayPreference(mScreen);
+
+        final AccessibilityFooterPreference footerPreference = mScreen.findPreference(TEST_KEY);
+        final String packageName = mContext.getString(R.string.accessibility_captioning_title);
+        final String iconContentDescription = mContext.getString(
+                R.string.accessibility_introduction_title,
+                packageName);
+        assertThat(footerPreference.getIconContentDescription()).isEqualTo(iconContentDescription);
+    }
+}