Tests for Nova instance diagnostics (microversion v2.48)

Existing instance diagnostics tests were moved to the new files
to test diagnostics for different microversions (2.1 and 2.48).

Depends-On: If0b1493cc5c1c7f0d9896dd68342ad4dea4f7da2

Change-Id: I7757c5beeea3d3b0bc15a51cafc5ea2ada65e76c
diff --git a/releasenotes/notes/add-server-diagnostics-validation-schema-b5a3c55b45aa718a.yaml b/releasenotes/notes/add-server-diagnostics-validation-schema-b5a3c55b45aa718a.yaml
new file mode 100644
index 0000000..e0ac87c
--- /dev/null
+++ b/releasenotes/notes/add-server-diagnostics-validation-schema-b5a3c55b45aa718a.yaml
@@ -0,0 +1,4 @@
+---
+features:
+  - |
+    Add validation schema for Nova server diagnostics API
\ No newline at end of file