[ReleasePR cosmos-db] [CosmosDB]Fixing bug from 2021-07-01-preview api version (#1937)

Create to sync Azure/azure-rest-api-specs#16126
[ReCreate this PR](https://github.com/azure-resource-manager-schemas/compare/main...AzureSDKAutomation:sdkAuto/cosmos-db?expand=1)

Author: msftbot[bot]

schemas/2021-07-01-preview/Microsoft.DocumentDB.json

@@ -3193,11 +3193,6 @@
     },
     "DatabaseAccountCreateUpdateProperties": {
       "type": "object",
-      "oneOf": [
-        {
-          "$ref": "#/definitions/DefaultRequestDatabaseAccountCreateUpdateProperties"
-        }
-      ],
       "properties": {
         "analyticalStorageConfiguration": {
           "oneOf": [
@@ -3284,6 +3279,21 @@
           ],
           "description": "The CORS policy for the Cosmos DB database account."
         },
+        "createMode": {
+          "oneOf": [
+            {
+              "type": "string",
+              "enum": [
+                "Default",
+                "Restore"
+              ]
+            },
+            {
+              "$ref": "https://schema.management.azure.com/schemas/common/definitions.json#/definitions/expression"
+            }
+          ],
+          "description": "Enum to indicate the mode of account creation."
+        },
         "databaseAccountOfferType": {
           "oneOf": [
             {
@@ -3504,6 +3514,7 @@
         }
       },
       "required": [
+        "createMode",
         "databaseAccountOfferType",
         "locations"
       ],
@@ -5444,21 +5455,6 @@
       },
       "description": "Properties of a managed Cassandra data center."
     },
-    "DefaultRequestDatabaseAccountCreateUpdateProperties": {
-      "type": "object",
-      "properties": {
-        "createMode": {
-          "type": "string",
-          "enum": [
-            "Default"
-          ]
-        }
-      },
-      "required": [
-        "createMode"
-      ],
-      "description": "Properties for non-restore Azure Cosmos DB database account requests."
-    },
     "DiagnosticLogSettings": {
       "type": "object",
       "properties": {