fix(ui5-radiobutton): fix keyboard handling on TAB/SHIFT+TAB (#231)

Author: fifoosid

packages/main/src/RadioButtonTemplateContext.js

@@ -25,7 +25,7 @@ class RadioButtonTemplateContext {
 			context = {
 				ctr: state,
 				readOnly: state.disabled || state.readOnly,
-				tabIndex: state.disabled ? undefined : "0",
+				tabIndex: state.disabled || (!state.selected && state.group) ? "-1" : "0",
 				circle: compact ? SVGConfig.compact : SVGConfig.default,
 				classes: { main: mainClasses, inner: innerClasses },
 				styles: {