CameraNDK: prevent double closing session

Bug: 27102995
Change-Id: Ie3e9870d1fc1025cab7a1019ed7d056fe07536ad
diff --git a/camera/ndk/impl/ACameraCaptureSession.h b/camera/ndk/impl/ACameraCaptureSession.h
index 1db1b21..f20b324 100644
--- a/camera/ndk/impl/ACameraCaptureSession.h
+++ b/camera/ndk/impl/ACameraCaptureSession.h
@@ -103,6 +103,7 @@
     const ACameraCaptureSession_stateCallbacks mUserSessionCallback;
     const wp<CameraDevice> mDevice;
     bool  mIsClosed = false;
+    bool  mClosedByApp = false;
     bool  mIdle = true;
     Mutex mSessionLock;
 };