title: AlertDialog not working properly on real device but on emulator
body: <p>My AlertDialog is not showing <code>setpositive</code> button <kbd>yes</kbd> and <code>setnegative</code> button <kbd>no</kbd> in real device but showing in emulator. When I run the app on a real device it shows the alert dialog but not <kbd>yes</kbd> and <kbd>no</kbd> in real device. The app runs very well on the emulator. It works very well on the real device too but the buttons are not visible.</p>
  
  <pre><code>private void showAddFoodDialog() {
      AlertDialog.Builder alertDialog = new AlertDialog.Builder(FoodList.this);
      alertDialog.setTitle("Add new Food");
      alertDialog.setMessage("please fill full information");
  
      LayoutInflater inflater=this.getLayoutInflater();
      View add_menu_layout= inflater.inflate(R.layout.add_new_food_layout,null);
  
      edtName = (MaterialEditText) add_menu_layout.findViewById(R.id.edtName);
      edtDescription = (MaterialEditText) add_menu_layout.findViewById(R.id.edtDescription);
      edtPrice = (MaterialEditText) add_menu_layout.findViewById(R.id.edtPrice);
      edtDiscount = (MaterialEditText) add_menu_layout.findViewById(R.id.edtDiscount);
      btnSelect = (FButton) add_menu_layout.findViewById(R.id.btnSelect);
      btnUpload = (FButton) add_menu_layout.findViewById(R.id.btnUpload);
  
      //event for button
      btnSelect.setOnClickListener(new View.OnClickListener() {
          @Override
          public void onClick(View v) {
              chooseImage(); //let user select image from gallery and save uri of  this image
          }
      });
  
      btnUpload.setOnClickListener(new View.OnClickListener() {
          @Override
          public void onClick(View v) {
              uploadImage();
          }
      });
      alertDialog.setView(add_menu_layout);
      alertDialog.setIcon(R.drawable.ic_shopping_cart_black_24dp);
  
      //set button
      alertDialog.setPositiveButton("YES", new DialogInterface.OnClickListener() {
          @Override
          public void onClick(DialogInterface dialog, int which) {
              dialog.dismiss();
              //here ,just create new category
              if (newFood !=null)
              {
                  foodList.push().setValue(newFood);
                  Snackbar.make(rootLayout,"New category "+newFood.getName()+" was added",Snackbar.LENGTH_SHORT).show();
              }
          }
      });
      alertDialog.setNegativeButton("NO", new DialogInterface.OnClickListener() {
          @Override
          public void onClick(DialogInterface dialog, int which) {
              dialog.dismiss();
          }
      });
      alertDialog.show();
  }
  </code></pre>