[ReleasePR apimanagement] {AzureAPIM} fixes Azure/azure-rest-api-specs#21849 'in body' parameter specification missing (#2736)

Create to sync Azure/azure-rest-api-specs#21875
[ReCreate this PR](https://github.com/azure-resource-manager-schemas/compare/main...azure-sdk:sdkAuto/apimanagement?expand=1)

Author: msftbot[bot]

schemas/2021-08-01/Microsoft.ApiManagement.json

@@ -1089,6 +1089,16 @@
           "maxLength": 80,
           "description": "Content type identifier."
         },
+        "properties": {
+          "oneOf": [
+            {
+              "$ref": "#/definitions/ContentTypeContractProperties"
+            },
+            {
+              "$ref": "https://schema.management.azure.com/schemas/common/definitions.json#/definitions/expression"
+            }
+          ]
+        },
         "resources": {
           "type": "array",
           "items": {
@@ -1109,6 +1119,7 @@
       "required": [
         "apiVersion",
         "name",
+        "properties",
         "type"
       ],
       "description": "Microsoft.ApiManagement/service/contentTypes"
@@ -1128,6 +1139,21 @@
           "maxLength": 80,
           "description": "Content item identifier."
         },
+        "properties": {
+          "oneOf": [
+            {
+              "type": "object",
+              "additionalProperties": {
+                "type": "object",
+                "properties": {}
+              },
+              "properties": {}
+            },
+            {
+              "$ref": "https://schema.management.azure.com/schemas/common/definitions.json#/definitions/expression"
+            }
+          ]
+        },
         "type": {
           "type": "string",
           "enum": [
@@ -1138,6 +1164,7 @@
       "required": [
         "apiVersion",
         "name",
+        "properties",
         "type"
       ],
       "description": "Microsoft.ApiManagement/service/contentTypes/contentItems"
@@ -3962,6 +3989,32 @@
       ],
       "description": "SSL certificate information."
     },
+    "ContentTypeContractProperties": {
+      "type": "object",
+      "properties": {
+        "description": {
+          "type": "string",
+          "description": "Content type description."
+        },
+        "id": {
+          "type": "string",
+          "description": "Content type identifier"
+        },
+        "name": {
+          "type": "string",
+          "description": "Content type name. Must be 1 to 250 characters long."
+        },
+        "schema": {
+          "type": "object",
+          "properties": {},
+          "description": "Content type schema."
+        },
+        "version": {
+          "type": "string",
+          "description": "Content type version."
+        }
+      }
+    },
     "DataMasking": {
       "type": "object",
       "properties": {
@@ -6563,6 +6616,16 @@
           "maxLength": 80,
           "description": "Content type identifier."
         },
+        "properties": {
+          "oneOf": [
+            {
+              "$ref": "#/definitions/ContentTypeContractProperties"
+            },
+            {
+              "$ref": "https://schema.management.azure.com/schemas/common/definitions.json#/definitions/expression"
+            }
+          ]
+        },
         "type": {
           "type": "string",
           "enum": [
@@ -6573,6 +6636,7 @@
       "required": [
         "apiVersion",
         "name",
+        "properties",
         "type"
       ],
       "description": "Microsoft.ApiManagement/service/contentTypes"
@@ -6592,6 +6656,21 @@
           "maxLength": 80,
           "description": "Content item identifier."
         },
+        "properties": {
+          "oneOf": [
+            {
+              "type": "object",
+              "additionalProperties": {
+                "type": "object",
+                "properties": {}
+              },
+              "properties": {}
+            },
+            {
+              "$ref": "https://schema.management.azure.com/schemas/common/definitions.json#/definitions/expression"
+            }
+          ]
+        },
         "type": {
           "type": "string",
           "enum": [
@@ -6602,6 +6681,7 @@
       "required": [
         "apiVersion",
         "name",
+        "properties",
         "type"
       ],
       "description": "Microsoft.ApiManagement/service/contentTypes/contentItems"