audioflinger: add HOTWORD audio source.

HOTWORD is a special capture audio source that uses
the same audio tuning as VOICE_RECOGNITION but allows an
active capture to be preempted.

Bug: 10640877.

Change-Id: Iea09a11cbcdbacc8d434e5230e7559dcd1b44ac0
diff --git a/services/audioflinger/ServiceUtilities.cpp b/services/audioflinger/ServiceUtilities.cpp
index 9ee513b..152455d 100644
--- a/services/audioflinger/ServiceUtilities.cpp
+++ b/services/audioflinger/ServiceUtilities.cpp
@@ -43,6 +43,13 @@
     return ok;
 }
 
+bool captureHotwordAllowed() {
+    static const String16 sCaptureHotwordAllowed("android.permission.CAPTURE_AUDIO_HOTWORD");
+    bool ok = checkCallingPermission(sCaptureHotwordAllowed);
+    if (!ok) ALOGE("android.permission.CAPTURE_AUDIO_HOTWORD");
+    return ok;
+}
+
 bool settingsAllowed() {
     if (getpid_cached == IPCThreadState::self()->getCallingPid()) return true;
     static const String16 sAudioSettings("android.permission.MODIFY_AUDIO_SETTINGS");