#2535 - Restoring default marker setting and adding null check. Making sprite field private to enforce using setter method for added protection.

android/java/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/annotations/Marker.java

@@ -2,6 +2,7 @@ package com.mapbox.mapboxsdk.annotations;
 
 import android.graphics.Point;
 import android.support.annotation.Nullable;
+import android.text.TextUtils;
 import android.view.View;
 import com.mapbox.mapboxsdk.R;
 import com.mapbox.mapboxsdk.geometry.LatLng;
@@ -19,7 +20,7 @@ public class Marker extends Annotation {
     LatLng position;
     float rotation;
     String snippet;
-    String sprite;
+    private String sprite = "default_marker";
     String title;
     private InfoWindow infoWindow = null;
 
@@ -140,7 +141,9 @@ public class Marker extends Annotation {
      * @param sprite The name of the sprite.
      */
     public void setSprite(@Nullable String sprite) {
-        this.sprite = sprite;
+        if (!TextUtils.isEmpty(sprite)) {
+            this.sprite = sprite;
+        }
     }
 
     public String getSprite() {

android/java/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/annotations/MarkerOptions.java

@@ -1,7 +1,6 @@
 package com.mapbox.mapboxsdk.annotations;
 
 import android.support.annotation.Nullable;
-
 import com.mapbox.mapboxsdk.geometry.LatLng;
 
 public class MarkerOptions extends AnnotationOptions {
@@ -101,7 +100,7 @@ public class MarkerOptions extends AnnotationOptions {
     }
 
     public MarkerOptions sprite(@Nullable String sprite) {
-        ((Marker)annotation).sprite = sprite;
+        ((Marker)annotation).setSprite(sprite);
         return this;
     }