[FAB-14103] fix unit test in gossip state metrics
[FAB-14103] fix unit test in gossip state metrics

There was an intermittent test failure 
due to a wrong assumption in the test.
Fixed by changing the test to deal with all possible scenarios.

Change-Id: I9ac9c6d5e51b2ae815fbff98a951f77ec5145d57
Signed-off-by: Hagar Meir <6d3fae9be567d337cd6461f97836a8e7a2123754@ibm.com>

manish-sethi/fabric-sidedb,stemlending/fabric,manish-sethi/fabric-sidedb,binhn/fabric,hyperledger/fabric,manish-sethi/fabric-sidedb,binhn/fabric,manish-sethi/fabric,manish-sethi/fabric,jimthematrix/fabric,manish-sethi/fabric-sidedb,binhn/fabric,jimthematrix/fabric,muralisrini/fabric,manish-sethi/fabric-sidedb,hyperledger/fabric,manish-sethi/fabric-sidedb,muralisrini/fabric,stemlending/fabric,muralisrini/fabric,stemlending/fabric,stemlending/fabric,manish-sethi/fabric-sidedb