[FlyCV] optimize the integration of FlyCV (#492)

* [Backend] fix lite backend save model error

* [Backend] fixed typos

* [FlyCV] optimize the integration of FlyCV

* [cmake] close some tests options

* [cmake] close some test option

* [FlyCV] remove un-need warnings

* [FlyCV] remove un-need GetMat method

* [FlyCV] optimize FlyCV codes

* [cmake] remove un-need cmake function in examples/CMakelists

* [cmake] support gflags for Android

fastdeploy/vision/common/processors/stride_pad.h

@@ -28,13 +28,13 @@ class FASTDEPLOY_DECL StridePad : public Processor {
   }
   bool ImplByOpenCV(Mat* mat);
 #ifdef ENABLE_FLYCV
-  bool ImplByFalconCV(Mat* mat);
+  bool ImplByFlyCV(Mat* mat);
 #endif
   std::string Name() { return "StridePad"; }
 
   static bool Run(Mat* mat, int stride,
                   const std::vector<float>& value = std::vector<float>(),
-                  ProcLib lib = ProcLib::OPENCV);
+                  ProcLib lib = ProcLib::DEFAULT);
 
  private:
   int stride_ = 32;