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.h b/services/audioflinger/ServiceUtilities.h
index 175cd28..531bc56 100644
--- a/services/audioflinger/ServiceUtilities.h
+++ b/services/audioflinger/ServiceUtilities.h
@@ -22,6 +22,7 @@
 
 bool recordingAllowed();
 bool captureAudioOutputAllowed();
+bool captureHotwordAllowed();
 bool settingsAllowed();
 bool dumpAllowed();