using Get-VstsTaskVariable to override parameters (#8004)

Author: dikhakha

Tasks/ServiceFabricDeployV1/task.json

@@ -17,7 +17,7 @@
     "version": {
         "Major": 1,
         "Minor": 7,
-        "Patch": 20
+        "Patch": 21
     },
     "demands": [
         "Cmd"

Tasks/ServiceFabricDeployV1/task.loc.json

@@ -17,7 +17,7 @@
   "version": {
     "Major": 1,
     "Minor": 7,
-    "Patch": 20
+    "Patch": 21
   },
   "demands": [
     "Cmd"

Tasks/ServiceFabricDeployV1/utilities.ps1

@@ -121,8 +121,8 @@ function Get-OverridenApplicationParameters
     $applicationManifestXml = [Xml] (Get-Content -LiteralPath $ApplicationManifestPath)
     foreach ($param in $applicationManifestXml.ApplicationManifest.Parameters.Parameter)
     {
-        $paramName = $param.Name -replace "\.", '_' -replace " ", '_'
-        $paramValue = (Get-Item env:$paramName -ErrorAction Ignore).Value
+        $paramName = $param.Name
+        $paramValue = Get-VstsTaskVariable -Name $paramName -ErrorAction Ignore
         if ($paramValue)
         {
             $overrideParameters.Add($paramName, $paramValue)