CameraNDK: implement abortCaptures API

Bug: 27102995
Change-Id: Idaf1db02e0bcc60bb9cdb2797b4479ea0389f5f9
diff --git a/camera/ndk/impl/ACameraCaptureSession.h b/camera/ndk/impl/ACameraCaptureSession.h
index f20b324..58428e6 100644
--- a/camera/ndk/impl/ACameraCaptureSession.h
+++ b/camera/ndk/impl/ACameraCaptureSession.h
@@ -77,6 +77,8 @@
 
     camera_status_t stopRepeating();
 
+    camera_status_t abortCaptures();
+
     camera_status_t setRepeatingRequest(
             /*optional*/ACameraCaptureSession_captureCallbacks* cbs,
             int numRequests, ACaptureRequest** requests,
@@ -104,7 +106,6 @@
     const wp<CameraDevice> mDevice;
     bool  mIsClosed = false;
     bool  mClosedByApp = false;
-    bool  mIdle = true;
     Mutex mSessionLock;
 };