title: Paypal currency convert upon checking out
body: <p>I was trying setup a paypal gateway but I was getting an error:</p>
  
  <p><code>Gateway Disabled: PayPal does not support your store currency</code></p>
  
  <p>By default, I have an AED Currency so I'm trying to convert it to USD when checking out to paypal but right now it is not working.
  I have this in my theme's <code>functons.php</code> file:</p>
  
  <pre><code>add_filter( 'woocommerce_currencies', 'add_my_currency' );
  
  function add_my_currency( $currencies ) {
       $currencies['AED'] = __( 'Emirati Dirham', 'woocommerce' );
       return $currencies;
  }
  
  add_filter('woocommerce_currency_symbol', 'add_my_currency_symbol', 10, 2);
  
  function add_my_currency_symbol( $currency_symbol, $currency ) {
       switch( $currency ) {
            case 'AED': $currency_symbol = 'AED'; break;
       }
       return $currency_symbol;
  }
  add_filter( 'loop_shop_per_page', create_function( '$cols', 'return 12;' ), 20 );
  
  add_filter( 'woocommerce_billing_fields', 'wc_billing_fields_state_filter', 10, 1 );
  
  function wc_billing_fields_state_filter( $address_fields ) {
      $address_fields['billing_state']['label'] = 'Emirate';
      $address_fields['billing_state']['placeholder'] = 'Emirate';
      return $address_fields;
  }
  </code></pre>
  
  <p>EDIT: I've deactivated the plugin "All Currencies for WooCommerce" and the settings menu is now showing. But PayPal Gateway is still not allowed since AED is not a supported currency. How do I convert it to USD upon paying with PayPal?</p>
  
  <p>The code above doesn't seem to work</p>