restoring the PurgeDisabled flag, to prevent this from being a breaking-change release

Author: Dragos Avadanei

src/ResourceManager/KeyVault/Commands.KeyVault/Models/KeyAttributes.cs

@@ -35,6 +35,7 @@ internal KeyAttributes(bool? enabled, DateTime? expires, DateTime? notBefore, st
             this.KeyType = keyType;
             this.KeyOps = keyOps;
             this.Tags = tags;
+            this.PurgeDisabled = false;
         }
 
         internal KeyAttributes(bool? enabled, DateTime? expires, DateTime? notBefore, string keyType, 
@@ -49,6 +50,7 @@ internal KeyAttributes(bool? enabled, DateTime? expires, DateTime? notBefore, st
             this.Updated = updated;
             this.RecoveryLevel = deletionRecoveryLevel;
             this.Tags = (tags == null) ? null : tags.ConvertToHashtable();
+            this.PurgeDisabled = false;
         }
 
         public bool? Enabled { get; set; }
@@ -65,6 +67,14 @@ internal KeyAttributes(bool? enabled, DateTime? expires, DateTime? notBefore, st
 
         public DateTime? Updated { get; private set; }
 
+        /// <summary>
+        /// Obsolete flag indicating that the key is protected against purge.
+        /// </summary>
+        /// <remarks>
+        /// Deprecated, will be removed in the next PowerShell release.
+        /// </remarks>
+        public bool PurgeDisabled { get; private set; }
+
         public string RecoveryLevel { get; private set; }
 
         public Hashtable Tags { get; set; }

src/ResourceManager/KeyVault/Commands.KeyVault/Models/SecretAttributes.cs

@@ -33,6 +33,7 @@ internal SecretAttributes(bool? enabled, DateTime? expires, DateTime? notBefore,
             this.NotBefore = notBefore;
             this.ContentType = contentType;
             this.Tags = tags;
+            this.PurgeDisabled = false;
         }
 
         internal SecretAttributes(bool? enabled, DateTime? expires, DateTime? notBefore, 
@@ -46,6 +47,7 @@ internal SecretAttributes(bool? enabled, DateTime? expires, DateTime? notBefore,
             this.ContentType = contentType;
             this.RecoveryLevel = deletionRecoveryLevel;
             this.Tags = (tags == null) ? null : tags.ConvertToHashtable();
+            this.PurgeDisabled = false;
         }
 
         public bool? Enabled { get; set; }
@@ -62,6 +64,14 @@ internal SecretAttributes(bool? enabled, DateTime? expires, DateTime? notBefore,
 
         public Hashtable Tags { get; set; }
 
+        /// <summary>
+        /// Obsolete flag indicating that the secret is protected against purge.
+        /// </summary>
+        /// <remarks>
+        /// Deprecated, will be removed in the next PowerShell release.
+        /// </remarks>
+        public bool PurgeDisabled { get; private set; }
+
         public string RecoveryLevel { get; private set; }
 
         public string TagsTable