Populates collection info count for A11y toggle feature pages.

This helps an accessibility service like TalkBack inform the user that
there are items that are skipped when navigating the list because they
are unimportant to accessibility.

Bug: 318607873
Test: atest AccessibilityFragmentUtilsTest
Test: atest ToggleScreenMagnificationPreferenceFragmentTest
Test: Enable TalkBack that supports the collection info count feature,
      open any of the pages from the bug, observe the item count and
      (un)important count are correct.
Flag: com.android.settings.accessibility.toggle_feature_fragment_collection_info
Change-Id: If64c89f2eb2f8301076baa79b9530124c850d2fc

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

@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2024 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.Preference;
+import androidx.test.core.app.ApplicationProvider;
+
+import com.android.settingslib.widget.IllustrationPreference;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+
+/** Tests for {@link AccessibilityFragmentUtils} */
+@RunWith(RobolectricTestRunner.class)
+public class AccessibilityFragmentUtilsTest {
+
+    private final Context mContext = ApplicationProvider.getApplicationContext();
+
+    @Test
+    public void isPreferenceImportantToA11y_basicPreference_isImportant() {
+        final Preference pref = new ShortcutPreference(mContext, /* attrs= */ null);
+
+        assertThat(AccessibilityFragmentUtils.isPreferenceImportantToA11y(pref)).isTrue();
+    }
+
+    @Test
+    public void isPreferenceImportantToA11y_illustrationPreference_hasContentDesc_isImportant() {
+        final IllustrationPreference pref =
+                new IllustrationPreference(mContext, /* attrs= */ null);
+        pref.setContentDescription("content desc");
+
+        assertThat(AccessibilityFragmentUtils.isPreferenceImportantToA11y(pref)).isTrue();
+    }
+
+    @Test
+    public void isPreferenceImportantToA11y_illustrationPreference_noContentDesc_notImportant() {
+        final IllustrationPreference pref =
+                new IllustrationPreference(mContext, /* attrs= */ null);
+        pref.setContentDescription(null);
+
+        assertThat(AccessibilityFragmentUtils.isPreferenceImportantToA11y(pref)).isFalse();
+    }
+
+    @Test
+    public void isPreferenceImportantToA11y_paletteListPreference_notImportant() {
+        final PaletteListPreference pref =
+                new PaletteListPreference(mContext, /* attrs= */ null);
+
+        assertThat(AccessibilityFragmentUtils.isPreferenceImportantToA11y(pref)).isFalse();
+    }
+}