[ReleasePR redis] [Hub Generated] [Microsoft.Cache] 2022-05-01 API: Add "Latest" option to "redisVersion" property, async linked server, managed identity changes (#2510)

Create to sync Azure/azure-rest-api-specs#19506
[ReCreate this PR](https://github.com/azure-resource-manager-schemas/compare/main...azure-sdk:sdkAuto/redis?expand=1)

Author: msftbot[bot]

schemas/2020-12-01/Microsoft.Cache.json

@@ -473,7 +473,7 @@
         },
         "redisVersion": {
           "type": "string",
-          "description": "Redis version. Only major version will be used in PUT/PATCH request with current valid values: (4, 6)"
+          "description": "Redis version. This should be in the form 'major[.minor[.build]]' (only 'major' is required) or the value 'latest' which refers to the latest stable Redis version that is available. Only the major and minor version are used in a PUT/PATCH request. Supported versions: 4.0, 6.0."
         },
         "replicasPerMaster": {
           "oneOf": [

schemas/2021-06-01/Microsoft.Cache.json

@@ -525,7 +525,7 @@
         },
         "redisVersion": {
           "type": "string",
-          "description": "Redis version. Only major version will be used in PUT/PATCH request with current valid values: (4, 6)"
+          "description": "Redis version. This should be in the form 'major[.minor[.build]]' (only 'major' is required) or the value 'latest' which refers to the latest stable Redis version that is available. Only the major and minor version are used in a PUT/PATCH request. Supported versions: 4.0, 6.0."
         },
         "replicasPerMaster": {
           "oneOf": [