Add "ERROR" to the SubmitRequirementResultInfo#Status field

This API field is mapped from the SubmitRequirementResult#Status field
which contains an "ERROR" entry. Error means that any of the
applicability, submittability or override expressions are non-parsable
due to invalid syntax.

Change-Id: I5f1847f64076d8e4be0c450f15d57704cf99abe4
diff --git a/Documentation/rest-api-changes.txt b/Documentation/rest-api-changes.txt
index d83ef0e..4d7df11 100644
--- a/Documentation/rest-api-changes.txt
+++ b/Documentation/rest-api-changes.txt
@@ -8246,7 +8246,7 @@
 Description of the submit requirement.
 |`status`||
 Status describing the result of evaluating the submit requirement. The status
-is one of (`SATISFIED`, `UNSATISFIED`, `OVERRIDDEN`, `NOT_APPLICABLE`).
+is one of (`SATISFIED`, `UNSATISFIED`, `OVERRIDDEN`, `NOT_APPLICABLE`, `ERROR`).
 |`is_legacy`||
 If true, this submit requirement result was created from a legacy
 link:#submit-record[SubmitRecord]. Otherwise, it was created by evaluating a
diff --git a/java/com/google/gerrit/extensions/common/SubmitRequirementResultInfo.java b/java/com/google/gerrit/extensions/common/SubmitRequirementResultInfo.java
index d17da0a..3d50f13 100644
--- a/java/com/google/gerrit/extensions/common/SubmitRequirementResultInfo.java
+++ b/java/com/google/gerrit/extensions/common/SubmitRequirementResultInfo.java
@@ -35,7 +35,13 @@
      * Submit requirement is not applicable for the change. Happens when {@code
      * applicabilityExpressionResult} is not fulfilled.
      */
-    NOT_APPLICABLE
+    NOT_APPLICABLE,
+
+    /**
+     * Any of the applicability, submittability or override expressions contain invalid syntax and
+     * are not parsable.
+     */
+    ERROR
   }
 
   /** Submit requirement name. */