Use same environment variable in docs.

docs/src/main/asciidoc/secret-management.adoc

@@ -45,14 +45,14 @@ spring:
   cloud:
     azure:
       profile:
-        tenant-id: ${TENANT_ID}
+        tenant-id: ${AZURE_TENANT_ID}
       credential:
-        client-id: ${CLIENT_ID}
-        client-secret: ${CLIENT_SECRET}
+        client-id: ${AZURE_CLIENT_ID}
+        client-secret: ${AZURE_CLIENT_SECRET}
       keyvault:
         secret:
           property-source-enabled: true
-          endpoint: ${ENDPOINT}
+          endpoint: ${KEY_VAULT_ENDPOINT}
 ----
 
 ===== Java code