Android/SwitchStyle: hide thumb text on Android 5.0

Change-Id: Ied63a5bd58a88f097ac9e20f30c21d45f45a2f46
Reviewed-by: Caroline Chao <caroline.chao@theqtcompany.com>

src/controls/Styles/Android/SwitchStyle.qml

@@ -79,6 +79,8 @@ SwitchStyle {
             Item {
                 id: thumb
 
+                readonly property bool hideText: AndroidStyle.styleDef.switchStyle.Switch_showText === false
+
                 x: control.checked ? max : min
 
                 TextMetrics {
@@ -126,6 +128,7 @@ SwitchStyle {
 
                 LabelStyle {
                     id: label
+                    visible: !thumb.hideText
                     text: control.checked ? panel.styleDef.Switch_textOn : panel.styleDef.Switch_textOff
 
                     pressed: control.pressed