Add server schema for microversion 2.26

This commit adds servers schema for microversion 2.26
Without those schema in this file, get_schema() method
will throw error about particular schema not found in this file.

Change-Id: I285b303e6b562ad819164c2951cde199ff761c7f
partially-implements: blueprint full-schema-for-all-microversions
diff --git a/tempest/lib/api_schema/response/compute/v2_26/servers.py b/tempest/lib/api_schema/response/compute/v2_26/servers.py
index 5c35eab..8e62dc3 100644
--- a/tempest/lib/api_schema/response/compute/v2_26/servers.py
+++ b/tempest/lib/api_schema/response/compute/v2_26/servers.py
@@ -15,7 +15,6 @@
 
 import copy
 
-from tempest.lib.api_schema.response.compute.v2_1 import servers as servers21
 from tempest.lib.api_schema.response.compute.v2_19 import servers as servers219
 
 # The 2.26 microversion changes the server GET and (detailed) LIST responses to
@@ -62,10 +61,6 @@
 rebuild_server_with_admin_pass['response_body']['properties']['server'][
     'required'].append('tags')
 
-# list response schema wasn't changed for v2.26 so use v2.1
-
-list_servers = copy.deepcopy(servers21.list_servers)
-
 list_tags = {
     'status_code': [200],
     'response_body': {
@@ -98,3 +93,11 @@
 }
 
 delete_tag = {'status_code': [204]}
+
+# NOTE(gmann): Below are the unchanged schema in this microversion. We need
+# to keep this schema in this file to have the generic way to select the
+# right schema based on self.schema_versions_info mapping in service client.
+# ****** Schemas unchanged since microversion 2.19 ******
+list_servers = copy.deepcopy(servers219.list_servers)
+show_server_diagnostics = copy.deepcopy(servers219.show_server_diagnostics)
+get_remote_consoles = copy.deepcopy(servers219.get_remote_consoles)