Import Android annotations instead of JavaX

Author: niknetniko

app/src/main/java/be/ugent/zeus/hydra/resto/RestoMeal.java

@@ -25,8 +25,9 @@
 import android.os.Parcel;
 import android.os.Parcelable;
 
+import androidx.annotation.Nullable;
+
 import java.util.List;
-import javax.annotation.Nullable;
 
 /**
  * Represents a meal.