CBQE-1315 Add wait for persistence to test_view_big_int_positive

Change-Id: I97be60afe25a65e4b183b6f702ef1b39f1aa3cfb
Reviewed-on: http://review.couchbase.org/26523
Reviewed-by: Deepkaran Salooja <deepkaran.salooja@globallogic.com>
Tested-by: Deepkaran Salooja <deepkaran.salooja@globallogic.com>