inline unnecessary local variable

Author: littleaj

core/src/main/java/com/microsoft/applicationinsights/internal/channel/common/SenderThreadsBackOffManager.java

@@ -83,8 +83,7 @@ public synchronized void stopAllSendersBackOffActivities() {
 
     @Override
     protected SenderThreadLocalBackOffData initialValue() {
-        long addSeconds = threadsSecondsDifference.incrementAndGet();
-        senderThreadLocalData = new SenderThreadLocalBackOffData(backOffTimeoutsInMilliseconds, addSeconds * 1000L);
+        senderThreadLocalData = new SenderThreadLocalBackOffData(backOffTimeoutsInMilliseconds, threadsSecondsDifference.incrementAndGet() * 1000L);
         registerSenderData(senderThreadLocalData);
         return senderThreadLocalData;
     }