Merge changes from topic "hearing-aid" into pi-dev

* changes:
  Add Feature Flag for Hearing Aid Profile
  To show hearing aids device in the available devices group

src/com/android/settings/bluetooth/AvailableMediaBluetoothDeviceUpdater.java

@@ -97,6 +97,11 @@ public class AvailableMediaBluetoothDeviceUpdater extends BluetoothDeviceUpdater
             if (DBG) {
                 Log.d(TAG, "isFilterMatched() current audio profile : " + currentAudioProfile);
             }
+            // If device is Hearing Aid, it is compatible with HFP and A2DP.
+            // It would show in Available Devices group.
+            if (cachedDevice.isConnectedHearingAidDevice()) {
+                return true;
+            }
             // According to the current audio profile type,
             // this page will show the bluetooth device that have corresponding profile.
             // For example:

src/com/android/settings/bluetooth/ConnectedBluetoothDeviceUpdater.java

@@ -97,6 +97,11 @@ public class ConnectedBluetoothDeviceUpdater extends BluetoothDeviceUpdater {
             if (DBG) {
                 Log.d(TAG, "isFilterMatched() current audio profile : " + currentAudioProfile);
             }
+            // If device is Hearing Aid, it is compatible with HFP and A2DP.
+            // It would not show in Connected Devices group.
+            if (cachedDevice.isConnectedHearingAidDevice()) {
+                return false;
+            }
             // According to the current audio profile type,
             // this page will show the bluetooth device that doesn't have corresponding profile.
             // For example:

src/com/android/settings/core/FeatureFlags.java

@@ -26,4 +26,5 @@ public class FeatureFlags {
     public static final String BLUETOOTH_WHILE_DRIVING = "settings_bluetooth_while_driving";
     public static final String DATA_USAGE_SETTINGS_V2 = "settings_data_usage_v2";
     public static final String AUDIO_SWITCHER_SETTINGS = "settings_audio_switcher";
+    public static final String HEARING_AID_SETTINGS = "settings_bluetooth_hearing_aid";
 }

src/com/android/settings/development/featureflags/FeatureFlagPersistent.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2018 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.featureflags;
+
+import android.content.Context;
+import android.os.SystemProperties;
+import android.support.annotation.VisibleForTesting;
+import android.text.TextUtils;
+import android.util.FeatureFlagUtils;
+import android.util.Log;
+
+import com.android.settings.core.FeatureFlags;
+
+import java.util.HashSet;
+
+/**
+ * Helper class to get feature persistent flag information.
+ */
+public class FeatureFlagPersistent {
+    private static final HashSet<String> PERSISTENT_FLAGS;
+    static {
+        PERSISTENT_FLAGS = new HashSet<>();
+        PERSISTENT_FLAGS.add(FeatureFlags.HEARING_AID_SETTINGS);
+    }
+
+    public static boolean isEnabled(Context context, String feature) {
+        String value = SystemProperties.get(FeatureFlagUtils.PERSIST_PREFIX + feature);
+        if (!TextUtils.isEmpty(value)) {
+            return Boolean.parseBoolean(value);
+        } else {
+            return FeatureFlagUtils.isEnabled(context, feature);
+        }
+    }
+
+    public static void setEnabled(Context context, String feature, boolean enabled) {
+        SystemProperties.set(FeatureFlagUtils.PERSIST_PREFIX + feature, enabled ? "true" : "false");
+        FeatureFlagUtils.setEnabled(context, feature, enabled);
+    }
+
+    public static boolean isPersistent(String feature) {
+        return PERSISTENT_FLAGS.contains(feature);
+    }
+
+    /**
+     * Returns all persistent flags in their raw form.
+     */
+    @VisibleForTesting(otherwise = VisibleForTesting.NONE)
+    static HashSet<String> getAllPersistentFlags() {
+        return PERSISTENT_FLAGS;
+    }
+}
+

src/com/android/settings/development/featureflags/FeatureFlagPreference.java

@@ -19,23 +19,36 @@ package com.android.settings.development.featureflags;
 import android.content.Context;
 import android.support.v14.preference.SwitchPreference;
 import android.util.FeatureFlagUtils;
+import android.util.Log;
 
 public class FeatureFlagPreference extends SwitchPreference {
 
     private final String mKey;
+    private final boolean mIsPersistent;
 
     public FeatureFlagPreference(Context context, String key) {
         super(context);
         mKey = key;
         setKey(key);
         setTitle(key);
-        setCheckedInternal(FeatureFlagUtils.isEnabled(context, mKey));
+        mIsPersistent = FeatureFlagPersistent.isPersistent(key);
+        boolean isFeatureEnabled;
+        if (mIsPersistent) {
+            isFeatureEnabled = FeatureFlagPersistent.isEnabled(context, key);
+        } else {
+            isFeatureEnabled = FeatureFlagUtils.isEnabled(context, key);
+        }
+        setCheckedInternal(isFeatureEnabled);
     }
 
     @Override
     public void setChecked(boolean isChecked) {
         setCheckedInternal(isChecked);
-        FeatureFlagUtils.setEnabled(getContext(), mKey, isChecked);
+        if (mIsPersistent) {
+            FeatureFlagPersistent.setEnabled(getContext(), mKey, isChecked);
+        } else {
+            FeatureFlagUtils.setEnabled(getContext(), mKey, isChecked);
+        }
     }
 
     private void setCheckedInternal(boolean isChecked) {