[ONOS-4616] YANG grouping linker issues fixed.

Change-Id: I741aa9ad1008c02c9a9f90cc117cd43729132129
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/io/impl/YangIoUtils.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/io/impl/YangIoUtils.java
index b505111..7120612 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/io/impl/YangIoUtils.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/utils/io/impl/YangIoUtils.java
@@ -433,7 +433,20 @@
         } else {
             stringBuilder.append(line + NEW_LINE);
         }
-        return stringBuilder.toString();
+
+        String[] strArray = stringBuilder.toString().split(NEW_LINE);
+        StringBuilder tempBuilder = new StringBuilder();
+        for (String str : strArray) {
+            if (str.length() > SUB_LINE_SIZE) {
+                if (str.contains(SPACE)) {
+                    String[] strArr = str.split(SPACE);
+                    tempBuilder = updateString(strArr, tempBuilder, SPACE, SUB_LINE_SIZE);
+                }
+            } else {
+                tempBuilder.append(str + NEW_LINE);
+            }
+        }
+        return tempBuilder.toString();
     }
 
     /*Updates the given line with the given size conditions.*/