Implementation of Bluetooth Audio HAL interface v2

This is the default implementation of Bluetooth Audio Hal v2, and 3
providers are defined.

* BluetoothAudioProvider is the default provider, which is a stub when
  no SessionType matched.
* A2dpSoftwareAudioProvider uses to replace the old A2DP legacy module
  and uses IPC via HIDL interface between Bluetooth stack and Audio HAL.
* HearingAidAudioProvider uses to replace the Hearing Aids module which
  uses UNIX socket as IPC and now there is HIDL based interface.

There is also a shared library named "libbluetooth_audio_session.so" to
provide the linkage directly between this HIDL and its HAL module,
bluetooth_audio. With this library, we can break the library dependency
and guarantee those symbols of libraries while compiling.

Bug: 111519504
Bug: 122503379
Test: boot and manual test

Change-Id: I54d86291482b7fb041a3ac3e171b68a4ed7bfa07
diff --git a/bluetooth/audio/2.0/default/BluetoothAudioProvidersFactory.h b/bluetooth/audio/2.0/default/BluetoothAudioProvidersFactory.h
new file mode 100644
index 0000000..0b51536
--- /dev/null
+++ b/bluetooth/audio/2.0/default/BluetoothAudioProvidersFactory.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright 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.
+ */
+
+#pragma once
+
+#include <android/hardware/bluetooth/audio/2.0/IBluetoothAudioProvidersFactory.h>
+
+#include "A2dpOffloadAudioProvider.h"
+#include "A2dpSoftwareAudioProvider.h"
+#include "BluetoothAudioProvider.h"
+#include "HearingAidAudioProvider.h"
+
+namespace android {
+namespace hardware {
+namespace bluetooth {
+namespace audio {
+namespace V2_0 {
+namespace implementation {
+
+class BluetoothAudioProvidersFactory : public IBluetoothAudioProvidersFactory {
+ public:
+  BluetoothAudioProvidersFactory() {}
+
+  Return<void> openProvider(const SessionType sessionType,
+                            openProvider_cb _hidl_cb) override;
+
+  Return<void> getProviderCapabilities(
+      const SessionType sessionType,
+      getProviderCapabilities_cb _hidl_cb) override;
+
+ private:
+  static A2dpSoftwareAudioProvider a2dp_software_provider_instance_;
+  static A2dpOffloadAudioProvider a2dp_offload_provider_instance_;
+  static HearingAidAudioProvider hearing_aid_provider_instance_;
+};
+
+extern "C" IBluetoothAudioProvidersFactory*
+HIDL_FETCH_IBluetoothAudioProvidersFactory(const char* name);
+
+}  // namespace implementation
+}  // namespace V2_0
+}  // namespace audio
+}  // namespace bluetooth
+}  // namespace hardware
+}  // namespace android