Fix warning for Android NDK compiler: "function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]"

https://stackoverflow.com/questions/42125/warning-error-function-declaration-isnt-a-prototype
In C int foo() and int foo(void) are different functions. int foo() accepts an arbitrary number of arguments, while int foo(void) accepts 0 arguments. In C++ they mean the same thing.

test/testautomation_video.c

@@ -624,7 +624,7 @@ int video_getWindowDisplayMode(void *arg)
 }
 
 /* Helper function that checks for an 'Invalid window' error */
-void _checkInvalidWindowError()
+void _checkInvalidWindowError(void)
 {
     const char *invalidWindowError = "Invalid window";
     char *lastError;
@@ -1300,7 +1300,7 @@ int video_getSetWindowPosition(void *arg)
 }
 
 /* Helper function that checks for an 'Invalid parameter' error */
-void _checkInvalidParameterError()
+void _checkInvalidParameterError(void)
 {
     const char *invalidParameterError = "Parameter";
     char *lastError;