[Service] Skip start service when app terminate & Check wrt-service launcher to 4s

[Service] Skip start service when app terminate & Check wrt-service launcher to 4s

Now an issue happen, service app is launched for a little time, then
wrt-service-launcher is killed by unknown reason, then wrt-service
start to stop, guess xwalk-extension is not stopped completely, at the
same time, service app is reqeusting preview, then crash happen, so
do below changes.

1. Skip start service when app is terminating.
2. Check wrt-service-launcher from 2s to 4s.

Change-Id: I4a7c4b946a89d1a1f6a46903e3582a1d91248888
Signed-off-by: liwei <wei90727.li@samsung.com>