[Fix] Service tags not added to health checks

Since commit 9685bdcd0b, service tags are added to the health checks.
Otherwise, when adding a service, tags are not added to its check.

In updateSyncState, we compare the checks of the local agent with the checks of the catalog.
It appears that the service tags are different (missing in one case), and so the check is synchronized.
That increase the ModifyIndex periodically when nothing changes.

Fixed it by adding serviceTags to the check.

Note that the issue appeared in version 0.8.2.
Looks related to #3259.

agent/agent.go

@@ -1603,6 +1603,7 @@ func (a *Agent) AddService(service *structs.NodeService, chkTypes []*structs.Che
 			Notes:       chkType.Notes,
 			ServiceID:   service.ID,
 			ServiceName: service.Service,
+			ServiceTags: service.Tags,
 		}
 		if chkType.Status != "" {
 			check.Status = chkType.Status

agent/agent_test.go

@@ -290,6 +290,7 @@ func TestAgent_AddService(t *testing.T) {
 					Notes:       "note1",
 					ServiceID:   "svcid1",
 					ServiceName: "svcname1",
+					ServiceTags: []string{"tag1"},
 				},
 			},
 		},
@@ -329,6 +330,7 @@ func TestAgent_AddService(t *testing.T) {
 					Notes:       "note1",
 					ServiceID:   "svcid2",
 					ServiceName: "svcname2",
+					ServiceTags: []string{"tag2"},
 				},
 				"check-noname": &structs.HealthCheck{
 					Node:        "node1",
@@ -337,6 +339,7 @@ func TestAgent_AddService(t *testing.T) {
 					Status:      "critical",
 					ServiceID:   "svcid2",
 					ServiceName: "svcname2",
+					ServiceTags: []string{"tag2"},
 				},
 				"service:svcid2:3": &structs.HealthCheck{
 					Node:        "node1",
@@ -345,6 +348,7 @@ func TestAgent_AddService(t *testing.T) {
 					Status:      "critical",
 					ServiceID:   "svcid2",
 					ServiceName: "svcname2",
+					ServiceTags: []string{"tag2"},
 				},
 				"service:svcid2:4": &structs.HealthCheck{
 					Node:        "node1",
@@ -353,6 +357,7 @@ func TestAgent_AddService(t *testing.T) {
 					Status:      "critical",
 					ServiceID:   "svcid2",
 					ServiceName: "svcname2",
+					ServiceTags: []string{"tag2"},
 				},
 			},
 		},