refactor(chartJs): remove label bg from polar chart

src/app/pages/charts/chartJs/chartJs.html

@@ -16,7 +16,7 @@
   <div class="col-md-4" ng-controller="chartJs1DCtrl">
     <div ba-panel ba-panel-title="Polar" ba-panel-class="with-scroll ">
       <canvas id="polar-area" class="chart chart-polar-area"
-              chart-data="data" chart-options="options" chart-labels="labels" chart-legend="true" chart-click="changeData">
+              chart-data="data" chart-options="polarOptions" chart-labels="labels" chart-legend="true" chart-click="changeData">
       </canvas>
     </div>
   </div>

src/app/pages/charts/chartJs/chartJs1DCtrl.js

@@ -14,8 +14,14 @@
     $scope.labels =["Sleeping", "Designing", "Coding", "Cycling"];
     $scope.data = [20, 40, 5, 35];
     $scope.options = {
-      segmentStrokeColor : "rgba(0,0,0,0)"
+      segmentShowStroke : false
     };
+
+    $scope.polarOptions = {
+      scaleShowLabelBackdrop : false,
+      segmentShowStroke : false
+    };
+
     $scope.changeData = function () {
       $scope.data = shuffle($scope.data);
     };