Fix definition of ManagedBy (#2364)

Author: flobernd

specification/_types/common.ts

@@ -77,11 +77,6 @@ export type Metrics = string | string[]
 
 export type ClusterAlias = string
 
-export type ManagedBy =
-  | 'Index Lifecycle Management'
-  | 'Data stream lifecycle'
-  | 'Unmanaged'
-
 export type Name = string
 export type Names = Name | Name[]
 

specification/indices/_types/DataStream.ts

@@ -22,14 +22,19 @@ import {
   Field,
   HealthStatus,
   IndexName,
-  ManagedBy,
   Metadata,
   Name,
   Uuid
 } from '@_types/common'
 import { integer } from '@_types/Numeric'
 import { DataStreamLifecycleWithRollover } from '@indices/_types/DataStreamLifecycle'
 
+enum ManagedBy {
+  'Index Lifecycle Management',
+  'Data stream lifecycle',
+  'Unmanaged'
+}
+
 export class DataStream {
   /**
    * Custom metadata for the stream, copied from the `_meta` object of the stream’s matching index template.