Allow running on newer Visual Studio 2017 versions

src/VisualStudio/IntegrationTest/TestUtilities/App.config

@@ -10,7 +10,7 @@
   <userSettings>
     <Microsoft.VisualStudio.IntegrationTest.Utilities.Settings>
       <setting name="VsProductVersion" serializeAs="String">
-        <value>15.0</value>
+        <value>15</value>
       </setting>
       <setting name="VsRootSuffix" serializeAs="String">
         <value>RoslynDev</value>

src/VisualStudio/IntegrationTest/TestUtilities/IntegrationHelper.cs

@@ -458,7 +458,6 @@ public static DTE TryLocateDteForProcess(Process process)
         {
             object dte = null;
             var monikers = new IMoniker[1];
-            var vsProgId = VisualStudioInstanceFactory.VsProgId;
 
             NativeMethods.GetRunningObjectTable(0, out var runningObjectTable);
             runningObjectTable.EnumRunning(out var enumMoniker);
@@ -484,16 +483,14 @@ public static DTE TryLocateDteForProcess(Process process)
                 moniker.GetDisplayName(bindContext, null, out var fullDisplayName);
 
                 // FullDisplayName will look something like: <ProgID>:<ProccessId>
-                if (!int.TryParse(fullDisplayName.Split(':').Last(), out var displayNameProcessId))
+                var displayNameParts = fullDisplayName.Split(':');
+                if (!int.TryParse(displayNameParts.Last(), out var displayNameProcessId))
                 {
                     continue;
                 }
 
-                var displayName = fullDisplayName.Substring(0, (fullDisplayName.Length - (displayNameProcessId.ToString().Length + 1)));
-                var fullProgId = vsProgId.StartsWith("!") ? vsProgId : $"!{vsProgId}";
-
-                if (displayName.Equals(fullProgId, StringComparison.OrdinalIgnoreCase) &&
-                    (displayNameProcessId == process.Id))
+                if (displayNameParts[0].StartsWith("!VisualStudio.DTE", StringComparison.OrdinalIgnoreCase) &&
+                    displayNameProcessId == process.Id)
                 {
                     runningObjectTable.GetObject(moniker, out dte);
                 }

src/VisualStudio/IntegrationTest/TestUtilities/Settings.Designer.cs

@@ -12,7 +12,7 @@ namespace Microsoft.VisualStudio.IntegrationTest.Utilities {
     
     
     [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]
-    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.VisualStudio.Editors.SettingsDesigner.SettingsSingleFileGenerator", "15.0.0.0")]
+    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.VisualStudio.Editors.SettingsDesigner.SettingsSingleFileGenerator", "15.3.0.0")]
     internal sealed partial class Settings : global::System.Configuration.ApplicationSettingsBase {
         
         private static Settings defaultInstance = ((Settings)(global::System.Configuration.ApplicationSettingsBase.Synchronized(new Settings())));
@@ -25,7 +25,7 @@ internal sealed partial class Settings : global::System.Configuration.Applicatio
         
         [global::System.Configuration.UserScopedSettingAttribute()]
         [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
-        [global::System.Configuration.DefaultSettingValueAttribute("15.0")]
+        [global::System.Configuration.DefaultSettingValueAttribute("15")]
         public string VsProductVersion {
             get {
                 return ((string)(this["VsProductVersion"]));

src/VisualStudio/IntegrationTest/TestUtilities/Settings.settings

@@ -3,7 +3,7 @@
   <Profiles />
   <Settings>
     <Setting Name="VsProductVersion" Type="System.String" Scope="User">
-      <Value Profile="(Default)">15.0</Value>
+      <Value Profile="(Default)">15</Value>
     </Setting>
     <Setting Name="VsRootSuffix" Type="System.String" Scope="User">
       <Value Profile="(Default)">RoslynDev</Value>

src/VisualStudio/IntegrationTest/TestUtilities/VisualStudioInstanceFactory.cs

@@ -20,8 +20,6 @@ public sealed class VisualStudioInstanceFactory : IDisposable
     {
         public static readonly string VsProductVersion = Settings.Default.VsProductVersion;
 
-        public static readonly string VsProgId = $"VisualStudio.DTE.{VsProductVersion}";
-
         public static readonly string VsLaunchArgs = $"{(string.IsNullOrWhiteSpace(Settings.Default.VsRootSuffix) ? "/log" : $"/rootsuffix {Settings.Default.VsRootSuffix}")} /log";
 
         /// <summary>