Revert "Add deprecation notice to GetOwner and SetOwner for groups"

As explained in change Id18851f503 we want to continue supporting the
GetOwner and SetOwner REST endpoints, hence revert the deprecation.

This reverts commit a61a631959a79ed0ba12673910e4d388b54ec050.

Change-Id: Ie311c6c694195d939c508f35dd0b4c0cffa2ec72
diff --git a/Documentation/rest-api-groups.txt b/Documentation/rest-api-groups.txt
index 23a1f96..63d0b40 100644
--- a/Documentation/rest-api-groups.txt
+++ b/Documentation/rest-api-groups.txt
@@ -771,8 +771,6 @@
 
 Retrieves the owner group of a Gerrit internal group.
 
-[NOTE] This endpoint is deprecated and will be removed in a future Gerrit release.
-
 .Request
 ----
   GET /groups/9999c971bb4ab872aab759d8c49833ee6b9ff320/owner HTTP/1.0
@@ -815,8 +813,6 @@
 The new owner can be specified by name, by group UUID or by the legacy
 numeric group ID.
 
-[NOTE] This endpoint is deprecated and will be removed in a future Gerrit release.
-
 .Request
 ----
   PUT /groups/9999c971bb4ab872aab759d8c49833ee6b9ff320/owner HTTP/1.0
diff --git a/java/com/google/gerrit/extensions/api/groups/GroupApi.java b/java/com/google/gerrit/extensions/api/groups/GroupApi.java
index 5137cdd..fe85eaa 100644
--- a/java/com/google/gerrit/extensions/api/groups/GroupApi.java
+++ b/java/com/google/gerrit/extensions/api/groups/GroupApi.java
@@ -40,12 +40,7 @@
    */
   void name(String name) throws RestApiException;
 
-  /**
-   * @return owning group info.
-   * @deprecated for groups in NoteDb, use READ/PUSH permissions on the group ref to express
-   *     ownership.
-   */
-  @Deprecated
+  /** @return owning group info. */
   GroupInfo owner() throws RestApiException;
 
   /**
@@ -53,10 +48,7 @@
    *
    * @param owner identifier of new group owner.
    * @throws RestApiException
-   * @deprecated for groups in NoteDb, use READ/PUSH permissions on the group ref to express
-   *     ownership.
    */
-  @Deprecated
   void owner(String owner) throws RestApiException;
 
   /** @return group description. */