Adjust version of hidden data streams (#64468)

This change adjust version used in data stream serialization for BwC.
It also fixes flaky yaml test by moving hidden template to the test itself instead of the setup

server/src/main/java/org/elasticsearch/cluster/metadata/DataStream.java

@@ -43,7 +43,7 @@ import java.util.Objects;
 public final class DataStream extends AbstractDiffable<DataStream> implements ToXContentObject {
 
     public static final String BACKING_INDEX_PREFIX = ".ds-";
-    public static final Version HIDDEN_VERSION = Version.V_8_0_0;
+    public static final Version HIDDEN_VERSION = Version.V_7_11_0;
 
     private final String name;
     private final TimestampField timeStampField;

x-pack/plugin/src/test/resources/rest-api-spec/test/data_stream/10_basic.yml

@@ -27,16 +27,6 @@ setup:
                   type: date_nanos
           data_stream: {}
 
-  - do:
-      allowed_warnings:
-        - "index template [my-template3] has index patterns [.hidden-data-stream,hidden-data-stream] matching patterns from existing older templates [global] with patterns (global => [*]); this template [my-template3] will take precedence during new index creation"
-      indices.put_index_template:
-        name: my-template3
-        body:
-          index_patterns: [.hidden-data-stream,hidden-data-stream]
-          data_stream:
-            hidden: true
-
 ---
 "Create data stream":
   - skip:
@@ -116,8 +106,17 @@ setup:
 ---
 "Create hidden data stream":
   - skip:
-      version: " - 7.99.99"
-      reason: "re-enable in 7.11 when backported"
+      version: " - 7.10.99"
+      reason: "hidden data streams only available in 7.11"
+  - do:
+      allowed_warnings:
+        - "index template [my-template3] has index patterns [.hidden-data-stream,hidden-data-stream] matching patterns from existing older templates [global] with patterns (global => [*]); this template [my-template3] will take precedence during new index creation"
+      indices.put_index_template:
+        name: my-template3
+        body:
+          index_patterns: [ .hidden-data-stream,hidden-data-stream ]
+          data_stream:
+            hidden: true
   - do:
       indices.create_data_stream:
         name: hidden-data-stream
@@ -196,6 +195,9 @@ setup:
         name: .hidden-data-stream
   - is_true: acknowledged
 
+  - do:
+      indices.delete_index_template:
+        name: my-template3
 ---
 "Create data stream with invalid name":
   - skip: