fix: decimal format of webRgbOrHex util method excludes trailing zero

Author: cjenkscybercom

app/display/representation-javafx/src/main/java/org/csstudio/display/builder/representation/javafx/JFXUtil.java

@@ -33,7 +33,7 @@
 public class JFXUtil extends org.phoebus.ui.javafx.JFXUtil
 {
     private static double font_calibration = 1.0;
-    private static final DecimalFormat RGBA_ALPHA_DECIMAL_FORMAT = new DecimalFormat("#.##");
+    private static final DecimalFormat RGBA_ALPHA_DECIMAL_FORMAT = new DecimalFormat("0.00");
 
     static
     {

app/display/representation-javafx/src/test/java/org/csstudio/display/builder/representation/javafx/JFXUtilTest.java

@@ -38,7 +38,7 @@ public void testRGB()
     {
         assertThat(JFXUtil.webRgbOrHex(new WidgetColor(15, 255, 0)), equalTo("#0FFF00"));
         assertThat(JFXUtil.webRgbOrHex(new WidgetColor(0, 16, 255)), equalTo("#0010FF"));
-        assertThat(JFXUtil.webRgbOrHex(new WidgetColor(0, 16, 255, 50)), equalTo("rgba(0,16,255,0.19607843)"));
+        assertThat(JFXUtil.webRgbOrHex(new WidgetColor(0, 16, 255, 50)), equalTo("rgba(0,16,255,0.20)"));
     }
 
     @Test