Fix the relative path issue in GetWebServiceDefinitionFromFile().

Root cause: GetFullPath() is based on the current process(powershell.exe) start point to generate the full path. But actually inside powershell, the user may already moved to another folder.

Author: Klein Hu

src/ResourceManager/MachineLearning/Commands.MachineLearning/Cmdlets/ImportWebServiceDefinition.cs

@@ -50,7 +50,9 @@ public override void ExecuteCmdlet()
                         ImportWebServiceDefinition.ImportFromFileParamSet, 
                         StringComparison.OrdinalIgnoreCase))
             {
-                jsonDefinition = CmdletHelpers.GetWebServiceDefinitionFromFile(this.InputFile);
+                jsonDefinition = CmdletHelpers.GetWebServiceDefinitionFromFile(
+                                        this.SessionState.Path.CurrentFileSystemLocation.Path, 
+                                        this.InputFile);
             }
 
             WebService serviceDefinition = ModelsSerializationUtil.GetAzureMLWebServiceFromJsonDefinition(jsonDefinition);

src/ResourceManager/MachineLearning/Commands.MachineLearning/Cmdlets/NewAzureMLWebService.cs

@@ -83,8 +83,12 @@ protected override void RunCmdlet()
                                 NewAzureMLWebService.CreateFromFileParameterSet,
                                 StringComparison.OrdinalIgnoreCase))
                     {
-                        string jsonDefinition = CmdletHelpers.GetWebServiceDefinitionFromFile(this.DefinitionFile);
-                        this.NewWebServiceDefinition = ModelsSerializationUtil.GetAzureMLWebServiceFromJsonDefinition(jsonDefinition);
+                        string jsonDefinition = 
+                                CmdletHelpers.GetWebServiceDefinitionFromFile(
+                                                this.SessionState.Path.CurrentFileSystemLocation.Path,
+                                                this.DefinitionFile);
+                        this.NewWebServiceDefinition = 
+                                ModelsSerializationUtil.GetAzureMLWebServiceFromJsonDefinition(jsonDefinition);
                     }
 
                     WebService newWebService =

src/ResourceManager/MachineLearning/Commands.MachineLearning/Utilities/CmdletHelpers.cs

@@ -49,10 +49,19 @@ internal static bool TryParseMlWebServiceMetadataFromResourceId(
             return false;
         }
 
-        internal static string GetWebServiceDefinitionFromFile(string definitionFilePath)
+        internal static string GetWebServiceDefinitionFromFile(string currentPath, string definitionFilePath)
         {
-            var definitionFileFullPath = Path.GetFullPath(definitionFilePath);
-            if (!File.Exists(definitionFileFullPath))
+            string definitionFileFullPath;
+            if (Path.IsPathRooted(definitionFilePath))
+            {
+                definitionFileFullPath = definitionFilePath;
+            }
+            else
+            {
+                definitionFileFullPath = Path.Combine(currentPath, definitionFilePath);
+            }
+
+            if (!File.Exists(definitionFilePath))
             {
                 throw new FileNotFoundException(Resources.MissingDefinitionFile, definitionFilePath);
             }