Fix size declarations for boolean ChangeFields

Change-Id: If4ed3f443af62f2cefa4be855e56f0328f8725ee
Release-Notes:skip
diff --git a/java/com/google/gerrit/server/index/change/ChangeField.java b/java/com/google/gerrit/server/index/change/ChangeField.java
index 7aefa63..59c968a 100644
--- a/java/com/google/gerrit/server/index/change/ChangeField.java
+++ b/java/com/google/gerrit/server/index/change/ChangeField.java
@@ -557,6 +557,7 @@
 
   public static final IndexedField<ChangeData, String> IS_PURE_REVERT_FIELD =
       IndexedField.<ChangeData>stringBuilder("IsPureRevert")
+          .size(1)
           .build(cd -> Boolean.TRUE.equals(cd.isPureRevert()) ? "1" : "0");
 
   public static final IndexedField<ChangeData, String>.SearchSpec IS_PURE_REVERT_SPEC =
@@ -568,6 +569,7 @@
    */
   public static final IndexedField<ChangeData, String> IS_SUBMITTABLE_FIELD =
       IndexedField.<ChangeData>stringBuilder("IsSubmittable")
+          .size(1)
           .build(
               cd ->
                   // All submit requirements should be fulfilled