[fix][client] Fix update response body text (#18794)

Author: tuteng

pulsar-broker/src/test/java/org/apache/pulsar/broker/admin/AdminApiSchemaTest.java

@@ -278,7 +278,7 @@ public void testInvalidSchemaDataException(ApiVersion version) {
             admin.schemas().createSchema(topicName, schemaInfo);
         } catch (PulsarAdminException e) {
             Assert.assertEquals(e.getStatusCode(), 422);
-            Assert.assertEquals(e.getMessage(), "HTTP 422 Invalid schema definition data for AVRO schema");
+            Assert.assertTrue(e.getMessage().contains("Invalid schema definition data for AVRO schema"));
         }
     }
 

pulsar-client-admin/src/main/java/org/apache/pulsar/client/admin/internal/http/AsyncHttpConnector.java

@@ -241,6 +241,9 @@ public Status.Family getFamily() {
 
                     @Override
                     public String getReasonPhrase() {
+                        if (response.hasResponseBody()) {
+                            return response.getResponseBody();
+                        }
                         return response.getStatusText();
                     }
                 });