fixing isValid function call bug (#188)

Author: prklm10

src/main/java/io/percy/appium/providers/GenericProvider.java

@@ -234,7 +234,7 @@ public void getRegionsByLocation(JSONArray elementsArray, List<Region> customLoc
         for (int index = 0; index < customLocations.size(); index++) {
             try {
                 Region customLocation = customLocations.get(index);
-                if (customLocation.isValid(width, height)) {
+                if (customLocation.isValid(height, width)) {
                     String selector = "custom region " + index;
                     JSONObject region = new JSONObject();
                     JSONObject coordinates = new JSONObject();

src/test/java/io/percy/appium/providers/GenericProviderTest.java

@@ -233,7 +233,12 @@ public void testGetRegionsByLocation() {
         customRegion.setBottom(100);
         customRegion.setLeft(200);
         customRegion.setRight(250);
+        // Dimensions are 1080x2160
+        Region invaliCustomRegion1 = new Region(2299, 2230, 200, 250);
+        Region invaliCustomRegion2 = new Region(50, 100, 1070, 1100);
         customLocations.add(customRegion);
+        customLocations.add(invaliCustomRegion1);
+        customLocations.add(invaliCustomRegion2);
 
         AndroidMetadata metadata = new AndroidMetadata(androidDriver, "dummy", null, null, null, null);
         GenericProvider genericProvider = new GenericProvider(androidDriver);