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_keyboard.c

@@ -102,7 +102,7 @@ int keyboard_getKeyFromName(void *arg)
 /*
  * Local helper to check for the invalid scancode error message
  */
-void _checkInvalidScancodeError()
+void _checkInvalidScancodeError(void)
 {
     const char *expectedError = "Parameter 'scancode' is invalid";
     const char *error;
@@ -574,7 +574,7 @@ int keyboard_getScancodeFromName(void *arg)
 /*
  * Local helper to check for the invalid scancode error message
  */
-void _checkInvalidNameError()
+void _checkInvalidNameError(void)
 {
     const char *expectedError = "Parameter 'name' is invalid";
     const char *error;