IT: Add constant for sleep time

IT: Add constant for sleep time

In addition, decrease sleep time for the multi-site tests from 2 seconds
to 1 second, to avoid the following type intermittent errors:

Failed tests:
  MappingServiceIntegrationTest.testMultiSite:414->testMultiSiteScenarioA:687
SMR contained Eid [_address=Ipv4PrefixBinary
[_ipv4AddressBinary=Ipv4AddressBinary [_value=[-64, 0, 1, 1]],
_ipv4MaskLength=32, augmentation=[]], _addressType=class
org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.binary.address.types.rev160504.Ipv4PrefixBinaryAfi,
_virtualNetworkId=InstanceIdType [_value=2], augmentation=[]] which
wasn't expected.

AND

Failed tests:
  MappingServiceIntegrationTest.testMultiSite:415->testMultiSiteScenarioB:802
SMR contained Eid [_address=Ipv4PrefixBinary
[_ipv4AddressBinary=Ipv4AddressBinary [_value=[-64, 0, 2, 5]],
_ipv4MaskLength=32, augmentation=[]], _addressType=class
org.opendaylight.yang.gen.v1.urn.opendaylight.lfm.lisp.binary.address.types.rev160504.Ipv4PrefixBinaryAfi,
_virtualNetworkId=InstanceIdType [_value=2], augmentation=[]] which
wasn't expected.

Change-Id: I551e1f6ba60fc54ab259a419cd8c5ce97eaa1ba9
Signed-off-by: Lorand Jakab <lojakab@cisco.com>