[ReleasePR authorization] add RBAC to 2020-10-01-preview autogen (#1876)

Create to sync Azure/azure-rest-api-specs#15836
[ReCreate this PR](https://github.com/azure-resource-manager-schemas/compare/main...AzureSDKAutomation:sdkAuto/authorization?expand=1)

Author: msftbot[bot]

schemas/2018-09-01-preview/Microsoft.Authorization.Authz.json

@@ -72,13 +72,7 @@
                 "User",
                 "Group",
                 "ServicePrincipal",
-                "Unknown",
-                "DirectoryRoleTemplate",
-                "ForeignGroup",
-                "Application",
-                "MSI",
-                "DirectoryObjectOrGroup",
-                "Everyone"
+                "ForeignGroup"
               ]
             },
             {

schemas/2020-03-01-preview/Microsoft.Authorization.Authz.json

@@ -84,13 +84,7 @@
                 "User",
                 "Group",
                 "ServicePrincipal",
-                "Unknown",
-                "DirectoryRoleTemplate",
-                "ForeignGroup",
-                "Application",
-                "MSI",
-                "DirectoryObjectOrGroup",
-                "Everyone"
+                "ForeignGroup"
               ]
             },
             {

schemas/2020-04-01-preview/Microsoft.Authorization.Authz.json

@@ -88,13 +88,7 @@
                 "User",
                 "Group",
                 "ServicePrincipal",
-                "Unknown",
-                "DirectoryRoleTemplate",
-                "ForeignGroup",
-                "Application",
-                "MSI",
-                "DirectoryObjectOrGroup",
-                "Everyone"
+                "ForeignGroup"
               ]
             },
             {

schemas/2020-08-01-preview/Microsoft.Authorization.Authz.json

@@ -77,13 +77,7 @@
                 "User",
                 "Group",
                 "ServicePrincipal",
-                "Unknown",
-                "DirectoryRoleTemplate",
-                "ForeignGroup",
-                "Application",
-                "MSI",
-                "DirectoryObjectOrGroup",
-                "Everyone"
+                "ForeignGroup"
               ]
             },
             {

schemas/2020-10-01-preview/Microsoft.Authorization.Authz.json

@@ -194,13 +194,7 @@
                 "User",
                 "Group",
                 "ServicePrincipal",
-                "Unknown",
-                "DirectoryRoleTemplate",
                 "ForeignGroup",
-                "Application",
-                "MSI",
-                "DirectoryObjectOrGroup",
-                "Everyone",
                 "Device"
               ]
             },