Camera: BufferManager: Don't attach/detach on every frame

- Maintain separate count of attached buffers
- Only attach when new buffers need to be allocated
- Only detach when a buffer needs to be freed
- Fix missing notification initializations
- Remove warning that's always logged

Bug: 28695173
Change-Id: I38e997fa1e69c2b8743e43eed31a6a08a6f9cd7a
diff --git a/services/camera/libcameraservice/device3/Camera3OutputStream.h b/services/camera/libcameraservice/device3/Camera3OutputStream.h
index a883448..7d28b05 100644
--- a/services/camera/libcameraservice/device3/Camera3OutputStream.h
+++ b/services/camera/libcameraservice/device3/Camera3OutputStream.h
@@ -131,6 +131,8 @@
           wp<Camera3OutputStream> mParent;
     };
 
+    virtual status_t detachBuffer(sp<GraphicBuffer>* buffer, int* fenceFd);
+
     /**
      * Set the graphic buffer manager to get/return the stream buffers.
      *