Camera: implement buffer managment API

Test: compile
Bug: 109829698
Change-Id: I3d95792282da52db9db6fd6a086bbd7b3ff9dca9
diff --git a/services/camera/libcameraservice/device3/Camera3IOStreamBase.h b/services/camera/libcameraservice/device3/Camera3IOStreamBase.h
index 0a31d44..48e9bbf 100644
--- a/services/camera/libcameraservice/device3/Camera3IOStreamBase.h
+++ b/services/camera/libcameraservice/device3/Camera3IOStreamBase.h
@@ -82,7 +82,7 @@
 
     virtual size_t   getBufferCountLocked();
 
-    virtual size_t   getHandoutOutputBufferCountLocked();
+    virtual size_t   getHandoutOutputBufferCountLocked() const;
 
     virtual size_t   getHandoutInputBufferCountLocked();