Fix CurrencyListTest when locale is not en_US

When declaring a fiat currency and only providing the currency code,
it uses the system locale to get the currency display name.
This potentially causes different sorting results in
testUpdateWhenNotSortNumerically when locale is not en_US.

Now, it specifies the en_US locale when defining the fiat currencies
for this test.

Fixes #2259

desktop/src/test/java/bisq/desktop/util/CurrencyListTest.java

@@ -25,6 +25,7 @@
 import com.google.common.collect.Lists;
 
 import java.util.ArrayList;
+import java.util.Currency;
 import java.util.List;
 import java.util.Locale;
 
@@ -44,8 +45,10 @@
 @PrepareForTest(Preferences.class)
 @PowerMockIgnore({"com.sun.org.apache.xerces.*", "javax.xml.*", "org.xml.*"})
 public class CurrencyListTest {
-    private static final TradeCurrency USD = new FiatCurrency("USD");
-    private static final TradeCurrency RUR = new FiatCurrency("RUR");
+    private static final Locale locale = new Locale("en", "US");
+
+    private static final TradeCurrency USD = new FiatCurrency(Currency.getInstance("USD"), locale);
+    private static final TradeCurrency RUR = new FiatCurrency(Currency.getInstance("RUR"), locale);
     private static final TradeCurrency BTC = new CryptoCurrency("BTC", "Bitcoin");
     private static final TradeCurrency ETH = new CryptoCurrency("ETH", "Ether");
     private static final TradeCurrency BSQ = new CryptoCurrency("BSQ", "Bisq Token");
@@ -56,7 +59,7 @@ public class CurrencyListTest {
 
     @Before
     public void setUp() {
-        Locale.setDefault(new Locale("en", "US"));
+        Locale.setDefault(locale);
 
         CurrencyPredicates predicates = mock(CurrencyPredicates.class);
         when(predicates.isCryptoCurrency(USD)).thenReturn(false);