test(NODE-3787): sync preferring error codes over messages (#3104)

Author: baileympearson

test/spec/server-discovery-and-monitoring/errors/prefer-error-code.json

@@ -52,7 +52,7 @@
       }
     },
     {
-      "description": "errmsg \"not writable primary\" gets ignored when error code exists",
+      "description": "errmsg \"not master\" gets ignored when error code exists",
       "applicationErrors": [
         {
           "address": "a:27017",
@@ -61,7 +61,7 @@
           "type": "command",
           "response": {
             "ok": 0,
-            "errmsg": "not writable primary",
+            "errmsg": "not master",
             "code": 1
           }
         }

test/spec/server-discovery-and-monitoring/errors/prefer-error-code.yml

@@ -29,15 +29,15 @@ phases:
     logicalSessionTimeoutMinutes: null
     setName: rs
 
-- description: errmsg "not writable primary" gets ignored when error code exists
+- description: errmsg "not master" gets ignored when error code exists
   applicationErrors:
   - address: a:27017
     when: afterHandshakeCompletes
     maxWireVersion: 9
     type: command
     response:
       ok: 0
-      errmsg: "not writable primary"
+      errmsg: "not master"  # NOTE: This needs to be "not master" and not "not writable primary".
       code: 1  # Not a "not writable primary" error code.
   outcome: *outcome