Remove only one Lambda Exp for JAVA 7

Remove a Lambda Exp and replace ConcurrentHashMap#computeIfAbsent() with
containsKey() and put() so that this app can be built using JAVA 7.

Test: Build

Signed-off-by: Taesu Lee <taesu82.lee@samsung.com>
Change-Id: I7ff8a3b5fc4673dfe05c5ecc9418d377f3ed4f2e

src/com/android/messaging/datamodel/DataModelImpl.java

@@ -252,8 +252,10 @@ public class DataModelImpl extends DataModel {
                 if (subId <= ParticipantData.DEFAULT_SELF_SUB_ID) {
                     subId = PhoneUtils.getDefault().getDefaultSmsSubscriptionId();
                 }
-                sConnectivityUtilInstanceCacheN.computeIfAbsent(
-                        subId, key -> new ConnectivityUtil(mContext, key));
+                if (!sConnectivityUtilInstanceCacheN.containsKey(subId)) {
+                    sConnectivityUtilInstanceCacheN.put(
+                            subId, new ConnectivityUtil(mContext, subId));
+                }
             }
         });
     }