[Hotword] Implement IsHotwordHardwareAvailable() using device types.

chromeos/audio/audio_device.cc

Index: chromeos/audio/audio_device.cc
diff --git a/chromeos/audio/audio_device.cc b/chromeos/audio/audio_device.cc
index a3abba035ed54118b9611760155de726a7c567b6..4f4b18cc7326b1b1c99c98e4ea353c6b89cd80cb 100644
--- a/chromeos/audio/audio_device.cc
+++ b/chromeos/audio/audio_device.cc
@@ -28,6 +28,7 @@ uint8 GetDevicePriority(AudioDeviceType type) {
     case AUDIO_TYPE_INTERNAL_MIC:
       return 1;
     case AUDIO_TYPE_KEYBOARD_MIC:
+    case AUDIO_TYPE_AOKR:
     case AUDIO_TYPE_OTHER:
     default:
       return 0;
@@ -55,6 +56,8 @@ std::string AudioDevice::GetTypeString(AudioDeviceType type) {
       return "INTERNAL_MIC";
     case AUDIO_TYPE_KEYBOARD_MIC:
       return "KEYBOARD_MIC";
+    case AUDIO_TYPE_AOKR:
+      return "AOKR";
     case AUDIO_TYPE_OTHER:
     default:
       return "OTHER";
@@ -80,6 +83,8 @@ AudioDeviceType AudioDevice::GetAudioType(
     return AUDIO_TYPE_HDMI;
   else if (node_type.find("INTERNAL_SPEAKER") != std::string::npos)
     return AUDIO_TYPE_INTERNAL_SPEAKER;
+  else if (node_type.find("AOKR") != std::string::npos)
+    return AUDIO_TYPE_AOKR;
   else
     return AUDIO_TYPE_OTHER;
 }