Waning fixes for Android samples

samples/android/native-activity/jni/native.cpp

@@ -28,7 +28,7 @@ struct Engine
     cv::Ptr<cv::VideoCapture> capture;
 };
 
-cv::Size calc_optimal_camera_resolution(const char* supported, int width, int height)
+static cv::Size calc_optimal_camera_resolution(const char* supported, int width, int height)
 {
     int frame_width = 0;
     int frame_height = 0;

samples/android/tutorial-2-mixedprocessing/jni/jni_part.cpp

@@ -8,7 +8,7 @@ using namespace std;
 using namespace cv;
 
 extern "C" {
-JNIEXPORT void JNICALL Java_org_opencv_samples_tutorial2_Tuturial2Activity_FindFeatures(JNIEnv*, jobject, jlong addrGray, jlong addrRgba);
+JNIEXPORT void JNICALL Java_org_opencv_samples_tutorial2_Tutorial2Activity_FindFeatures(JNIEnv*, jobject, jlong addrGray, jlong addrRgba);
 
 JNIEXPORT void JNICALL Java_org_opencv_samples_tutorial2_Tutorial2Activity_FindFeatures(JNIEnv*, jobject, jlong addrGray, jlong addrRgba)
 {