tests: Check the usable bounds for centered window positioning

SDL now centers windows according to the usable display bounds, so the window centering test requires an update for the new behavior.

test/testautomation_video.c

@@ -1680,15 +1680,15 @@ static int video_setWindowCenteredOnDisplay(void *arg)
     if (displays) {
 
         /* Get display bounds */
-        result = SDL_GetDisplayBounds(displays[0 % displayNum], &display0);
-        SDLTest_AssertPass("SDL_GetDisplayBounds()");
+        result = SDL_GetDisplayUsableBounds(displays[0 % displayNum], &display0);
+        SDLTest_AssertPass("SDL_GetDisplayUsableBounds()");
         SDLTest_AssertCheck(result == 0, "Verify return value; expected: 0, got: %d", result);
         if (result != 0) {
             return TEST_ABORTED;
         }
 
-        result = SDL_GetDisplayBounds(displays[1 % displayNum], &display1);
-        SDLTest_AssertPass("SDL_GetDisplayBounds()");
+        result = SDL_GetDisplayUsableBounds(displays[1 % displayNum], &display1);
+        SDLTest_AssertPass("SDL_GetDisplayUsableBounds()");
         SDLTest_AssertCheck(result == 0, "Verify return value; expected: 0, got: %d", result);
         if (result != 0) {
             return TEST_ABORTED;