Remove the 2 seconds wait time to sync app data usage list.

- in v2, completely remove the asyn task to force update the network
stats since the network stats apis is actually not used.
- in v1, remove the 2s delay and only update the list when the asyn task
is done.

Change-Id: I10e887022d07fe38504036cbf3f12362eec939b3
Fixes: 119562454
Test: manual