Fix robot comment id field names in changes REST documentation

The fields are named robot_run_id and robot_id in the JSON output,
but the examples showed them as robotRunId and robotId.

Change-Id: Ie0e8e0035fe4c067a6e192ca4c33453192197a63
diff --git a/Documentation/rest-api-changes.txt b/Documentation/rest-api-changes.txt
index a7367f3..96f367f 100644
--- a/Documentation/rest-api-changes.txt
+++ b/Documentation/rest-api-changes.txt
@@ -1962,8 +1962,8 @@
           "name": "Code Analyzer",
           "email": "code.analyzer@example.com"
         },
-        "robotId": "importChecker",
-        "robotRunId": "76b1375aa8626ea7149792831fe2ed85e80d9e04"
+        "robot_id": "importChecker",
+        "robot_run_id": "76b1375aa8626ea7149792831fe2ed85e80d9e04"
       },
       {
         "id": "TveXwFiA",
@@ -1975,8 +1975,8 @@
           "name": "Code Analyzer",
           "email": "code.analyzer@example.com"
         },
-        "robotId": "styleChecker",
-        "robotRunId": "5c606c425dd45184484f9d0a2ffd725a7607839b"
+        "robot_id": "styleChecker",
+        "robot_run_id": "5c606c425dd45184484f9d0a2ffd725a7607839b"
       }
     ]
   }
@@ -4719,8 +4719,8 @@
           "name": "Code Analyzer",
           "email": "code.analyzer@example.com"
         },
-        "robotId": "importChecker",
-        "robotRunId": "76b1375aa8626ea7149792831fe2ed85e80d9e04"
+        "robot_id": "importChecker",
+        "robot_run_id": "76b1375aa8626ea7149792831fe2ed85e80d9e04"
       },
       {
         "id": "TveXwFiA",
@@ -4732,8 +4732,8 @@
           "name": "Code Analyzer",
           "email": "code.analyzer@example.com"
         },
-        "robotId": "styleChecker",
-        "robotRunId": "5c606c425dd45184484f9d0a2ffd725a7607839b"
+        "robot_id": "styleChecker",
+        "robot_run_id": "5c606c425dd45184484f9d0a2ffd725a7607839b"
       }
     ]
   }
@@ -4773,8 +4773,8 @@
       "name": "Code Analyzer",
       "email": "code.analyzer@example.com"
     },
-    "robotId": "importChecker",
-    "robotRunId": "76b1375aa8626ea7149792831fe2ed85e80d9e04"
+    "robot_id": "importChecker",
+    "robot_run_id": "76b1375aa8626ea7149792831fe2ed85e80d9e04"
   }
 ----