Add LE Audio feature switcher in the developer option menu

Add a switcher to enable/disable LE audio feature. The switcher could be
enabled by setprop ro.bluetooth.leaudio_offload.supported=true

screenshot: https://screenshot.googleplex.com/6aGP664S9PX5EMS

Bug: 233018305
Bug: 233005340
Test: make RunSettingsRoboTests ROBOTEST_FILTER=BluetoothLeAudioPreferenceControllerTest
Test: switch LE audio feature, and check LE audio functionality status
Change-Id: I8adcf27edd1438df445d32fca93f35ff5020a3b3

src/com/android/settings/development/BluetoothLeAudioPreferenceController.java

@@ -0,0 +1,114 @@
+/*
+ * Copyright 2022 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.development;
+
+import android.bluetooth.BluetoothAdapter;
+import android.bluetooth.BluetoothManager;
+import android.bluetooth.BluetoothStatusCodes;
+import android.content.Context;
+import android.os.SystemProperties;
+
+import androidx.annotation.VisibleForTesting;
+import androidx.preference.Preference;
+import androidx.preference.SwitchPreference;
+
+import com.android.settings.core.PreferenceControllerMixin;
+import com.android.settingslib.development.DeveloperOptionsPreferenceController;
+
+/**
+ * Preference controller to control Bluetooth LE audio feature
+ */
+public class BluetoothLeAudioPreferenceController
+        extends DeveloperOptionsPreferenceController
+        implements Preference.OnPreferenceChangeListener, PreferenceControllerMixin {
+
+    private static final String PREFERENCE_KEY = "bluetooth_enable_leaudio";
+
+    private static final String LE_AUDIO_DYNAMIC_SWITCH_PROPERTY =
+            "ro.bluetooth.leaudio_switcher.supported";
+    @VisibleForTesting
+    static final String LE_AUDIO_DYNAMIC_ENABLED_PROPERTY =
+            "persist.bluetooth.leaudio_switcher.enabled";
+
+    private final DevelopmentSettingsDashboardFragment mFragment;
+
+    @VisibleForTesting
+    BluetoothAdapter mBluetoothAdapter;
+
+    @VisibleForTesting
+    boolean mChanged = false;
+
+    public BluetoothLeAudioPreferenceController(Context context,
+            DevelopmentSettingsDashboardFragment fragment) {
+        super(context);
+        mFragment = fragment;
+        mBluetoothAdapter = context.getSystemService(BluetoothManager.class).getAdapter();
+    }
+
+    @Override
+    public String getPreferenceKey() {
+        return PREFERENCE_KEY;
+    }
+
+    @Override
+    public boolean onPreferenceChange(Preference preference, Object newValue) {
+        BluetoothRebootDialog.show(mFragment);
+        mChanged = true;
+        return false;
+    }
+
+    @Override
+    public void updateState(Preference preference) {
+        if (mBluetoothAdapter == null) {
+            return;
+        }
+
+        final boolean leAudioEnabled =
+                (mBluetoothAdapter.isLeAudioSupported() == BluetoothStatusCodes.FEATURE_SUPPORTED);
+        ((SwitchPreference) mPreference).setChecked(leAudioEnabled);
+
+        final boolean leAudioSwitchSupported =
+                SystemProperties.getBoolean(LE_AUDIO_DYNAMIC_SWITCH_PROPERTY, false);
+        if (!leAudioSwitchSupported) {
+            mPreference.setEnabled(false);
+        } else {
+            SystemProperties.set(LE_AUDIO_DYNAMIC_ENABLED_PROPERTY,
+                    Boolean.toString(leAudioEnabled));
+        }
+    }
+
+    /**
+     * Called when the RebootDialog confirm is clicked.
+     */
+    public void onRebootDialogConfirmed() {
+        if (!mChanged || mBluetoothAdapter == null) {
+            return;
+        }
+
+        final boolean leAudioEnabled =
+                (mBluetoothAdapter.isLeAudioSupported() == BluetoothStatusCodes.FEATURE_SUPPORTED);
+        SystemProperties.set(LE_AUDIO_DYNAMIC_ENABLED_PROPERTY,
+                Boolean.toString(!leAudioEnabled));
+    }
+
+    /**
+     * Called when the RebootDialog cancel is clicked.
+     */
+    public void onRebootDialogCanceled() {
+        mChanged = false;
+    }
+}