[Pair hearing devices] Add "Saved devices" to show bonded but not connected hearing devices

* BaseHearingDevicePreferenceController will also be used in "Hearing devices", so extract to parent class first.

Bug: 237625815
Test: make RunSettingsRoboTests ROBOTEST_FILTER="(SavedHearingDeviceUpdaterTest|BaseBluetoothDevicePreferenceControllerTest|BluetoothDeviceUpdaterTest|AvailableMediaBluetoothDeviceUpdaterTest|ConnectedBluetoothDeviceUpdaterTest|SavedBluetoothDeviceUpdaterTest)"
Change-Id: I8a492866f48e3a664b9ff78bce5a4f082c0dc465

src/com/android/settings/accessibility/SavedHearingDeviceUpdater.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2023 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 android.bluetooth.BluetoothDevice;
+import android.content.Context;
+
+import com.android.settings.bluetooth.SavedBluetoothDeviceUpdater;
+import com.android.settings.connecteddevice.DevicePreferenceCallback;
+import com.android.settingslib.bluetooth.CachedBluetoothDevice;
+
+/**
+ * Maintains and updates saved (bonded but not connected) hearing devices, including ASHA and HAP
+ * profile.
+ */
+public class SavedHearingDeviceUpdater extends SavedBluetoothDeviceUpdater {
+
+    private static final String PREF_KEY = "saved_hearing_device";
+
+    public SavedHearingDeviceUpdater(Context context,
+            DevicePreferenceCallback devicePreferenceCallback, int metricsCategory) {
+        super(context, devicePreferenceCallback, /* showConnectedDevice= */ false, metricsCategory);
+    }
+
+    @Override
+    public boolean isFilterMatched(CachedBluetoothDevice cachedDevice) {
+        final BluetoothDevice device = cachedDevice.getDevice();
+        final boolean isSavedHearingAidDevice = cachedDevice.isHearingAidDevice()
+                && device.getBondState() == BluetoothDevice.BOND_BONDED
+                && !device.isConnected();
+
+        return isSavedHearingAidDevice && isDeviceInCachedDevicesList(cachedDevice);
+    }
+
+    @Override
+    protected String getPreferenceKey() {
+        return PREF_KEY;
+    }
+}