[release/v7.7.0-preview.1] Enable usage in AppContainers (#27305)

Co-authored-by: Patrick Meinecke <SeeminglyScience@users.noreply.github.com>
Co-authored-by: Travis Plunk <travis.plunk@microsoft.com>

src/System.Management.Automation/engine/Modules/ModuleIntrinsics.cs

@@ -967,7 +967,9 @@ namespace System.Management.Automation
 #if UNIX
             return Platform.SelectProductNameForDirectory(Platform.XDG_Type.USER_MODULES);
 #else
-            string myDocumentsPath = InternalTestHooks.SetMyDocumentsSpecialFolderToBlank ? string.Empty : Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
+            string myDocumentsPath = InternalTestHooks.SetMyDocumentsSpecialFolderToBlank
+                ? string.Empty
+                : Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments, Environment.SpecialFolderOption.DoNotVerify);
             return string.IsNullOrEmpty(myDocumentsPath) ? null : Path.Combine(myDocumentsPath, Utils.ModuleDirectory);
 #endif
         }

src/System.Management.Automation/namespaces/FileSystemProvider.cs

@@ -569,7 +569,7 @@ namespace Microsoft.PowerShell.Commands
             if (driveIsFixed)
             {
                 // Since the drive is fixed, ensure the root is valid.
-                validDrive = Directory.Exists(drive.Root);
+                validDrive = SafeDoesPathExist(drive.Root);
             }
 
             if (validDrive)
@@ -908,7 +908,7 @@ namespace Microsoft.PowerShell.Commands
 
                         if (newDrive.DriveType == DriveType.Fixed)
                         {
-                            if (!newDrive.RootDirectory.Exists)
+                            if (!SafeDoesPathExist(newDrive.RootDirectory.FullName))
                             {
                                 continue;
                             }
@@ -1227,6 +1227,29 @@ namespace Microsoft.PowerShell.Commands
             }
         }
 
+        private static bool SafeDoesPathExist(string rootDirectory)
+        {
+            if (Directory.Exists(rootDirectory))
+            {
+                return true;
+            }
+
+            try
+            {
+                return (File.GetAttributes(rootDirectory) & FileAttributes.Directory) is not 0;
+            }
+            // In some scenarios (like AppContainers) direct access to the root directory may
+            // be prevented, but more specific paths may be accessible.
+            catch (UnauthorizedAccessException)
+            {
+                return true;
+            }
+            catch
+            {
+                return false;
+            }
+        }
+
         private FileSystemInfo GetFileSystemItem(string path, ref bool isContainer, bool showHidden)
         {
             path = NormalizePath(path);