CDRIVER-4349 unskip /Client/get_handshake_hello_response/pooled and relax assertion. (#1436)

* check for `Unknown` or `PossiblePrimary`

* unskip `/Client/get_handshake_hello_response/pooled`

Author: kevinAlbs

.evergreen/etc/skip-tests.txt

@@ -27,7 +27,6 @@
 
 /change_stream/live/track_resume_token # (CDRIVER-4344) Condition 'bson_compare (resume_token, &doc2_rt) == 0' failed
 /ClientPool/pop_timeout # (CDRIVER-4348) precondition failed: duration_usec / 1000 >= 1990
-/Client/get_handshake_hello_response/pooled # (CDRIVER-4349) Assert Failure: "Unknown" != "PossiblePrimary"
 
 /change_streams/legacy/change-streams # (CDRIVER-4350) Could not establish stream for node 127.0.0.1:8000: [TLS handshake failed: Connection timed out calling hello on '127.0.0.1:8000']
 /change_streams/legacy/change-streams-resume-allowlist # (CDRIVER-4350) Could not establish stream for node 127.0.0.1:8000: [TLS handshake failed: Connection timed out calling hello on '127.0.0.1:8000']

src/libmongoc/tests/test-mongoc-client.c

@@ -4089,7 +4089,18 @@ test_mongoc_client_get_handshake_hello_response_pooled (void)
    invalidated_sd =
       mongoc_client_get_server_description (client, monitor_sd->id);
    BSON_ASSERT (NULL != invalidated_sd);
-   ASSERT_CMPSTR ("Unknown", mongoc_server_description_type (invalidated_sd));
+
+   // Check the resulting server description.
+   // Invalidating sets the type to Unknown.
+   // A background monitor may have set the type to PossiblePrimary.
+   const char *got_description_type =
+      mongoc_server_description_type (invalidated_sd);
+   if (0 != strcmp ("Unknown", got_description_type) &&
+       0 != strcmp ("PossiblePrimary", got_description_type)) {
+      test_error ("Expected server to have type 'Unknown' or "
+                  "'PossiblePrimary', got: '%s'",
+                  got_description_type);
+   }
 
    /* The previously established connection should have a valid server
     * description. */