fix(ForceScrollBar): use transparent color in background

tests/ui/Linphone/Constants.qml

@@ -7,10 +7,11 @@ QtObject {
 
     // TODO: Mutualize similar colors.
     property QtObject colors: QtObject {
-        property string a: '#808080'
+        property string a: 'transparent'
         property string b: '#5E5E5F'
         property string c: '#C5C5C5'
         property string d: '#5A585B'
         property string e: '#DEDEDE'
+        property string f: '#808080'
     }
 }

tests/ui/Linphone/Styles/PopupStyle.qml

@@ -9,6 +9,6 @@ QtObject {
         property int horizontalOffset: 0
         property int samples: 15
         property int verticalOffset: 2
-        property string color: Constants.colors.a
+        property string color: Constants.colors.f
     }
 }

tests/ui/Linphone/Styles/ScrollBarStyle.qml

@@ -8,7 +8,7 @@ QtObject {
     property string pressedColor: Constants.colors.b
 
     property Rectangle background: Rectangle {
-        color: Constants.colors.d
+        color: Constants.colors.a
     }
 
     property Rectangle contentItem: Rectangle {

tests/ui/Linphone/Styles/SearchBoxStyle.qml

@@ -4,7 +4,7 @@ import QtQuick 2.7
 import Linphone 1.0
 
 QtObject {
-    property string shadowColor: Constants.colors.a
+    property string shadowColor: Constants.colors.f
 
     property Rectangle searchFieldBackground: Rectangle {
         implicitHeight: 30

tests/ui/Views/MainWindow/MainWindow.qml

@@ -167,7 +167,7 @@ ApplicationWindow {
         Loader {
             Layout.fillHeight: true
             Layout.fillWidth: true
-            source: 'qrc:/ui/Views/MainWindow/Home.qml'
+            source: 'qrc:/ui/Views/MainWindow/Conversation.qml'
         }
     }