Fix bug in breaking down indices

Author: pawankartik-elastic

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/parser/IdentifierBuilder.java

@@ -275,18 +275,22 @@ private static String[] breakPatternIntoIndices(String pattern) {
         var inDateMathExpr = false;
         for (int i = 0; i < pattern.length(); i++) {
             char c = pattern.charAt(i);
+            sb.append(c);
             if (c == '<') {
                 inDateMathExpr = true;
-                sb.append(c);
             } else if (c == '>') {
                 inDateMathExpr = false;
-                sb.append(c);
             } else if (c == '|' && inDateMathExpr == false) {
+                sb.deleteCharAt(sb.length() - 1);
                 indices.add(sb.toString());
                 sb.setLength(0);
             }
         }
 
+        if (sb.isEmpty() == false) {
+            indices.add(sb.toString());
+        }
+
         return indices.toArray(new String[0]);
     }