Merge pull request #63519 from MrHohn/ingress-upgrade-ig-size

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

[e2e ingress-gce] Change ingress-upgrade test to not check for number of instances

**What this PR does / why we need it**:
From #62710 and #63500, ingress-upgrade test is failing on asserting resources are intact after cluster upgrade because some instances appear to be absent from the instance group.

This PR stubs out the number of instances during verification as that is out of ingress controller's control.

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #NONE 

**Special notes for your reviewer**:
/assign @rramkumar1 
cc @bowei 

**Release note**:

```release-note
NONE
```

test/e2e/upgrades/ingress.go

@@ -177,6 +177,14 @@ func (t *IngressUpgradeTest) verify(f *framework.Framework, done <-chan struct{}
 	postUpgradeResourceStore := &GCPResourceStore{}
 	t.populateGCPResourceStore(postUpgradeResourceStore)
 
+	// Stub out the number of instances as that is out of Ingress controller's control.
+	for _, ig := range t.resourceStore.IgList {
+		ig.Size = 0
+	}
+	for _, ig := range postUpgradeResourceStore.IgList {
+		ig.Size = 0
+	}
+
 	framework.ExpectNoError(compareGCPResourceStores(t.resourceStore, postUpgradeResourceStore, func(v1 reflect.Value, v2 reflect.Value) error {
 		i1 := v1.Interface()
 		i2 := v2.Interface()