fix(e2e): use invalid UserAssignedIdentityID instead of invalid AADResource in scenario Flatcar_SecureTLSBootstrapping_BootstrapToken_Fallback (#7495)

Author: cameronmeissner

e2e/scenario_test.go

@@ -171,9 +171,9 @@ func Test_Flatcar_SecureTLSBootstrapping_BootstrapToken_Fallback(t *testing.T) {
 			VHD:     config.VHDFlatcarGen2,
 			BootstrapConfigMutator: func(nbc *datamodel.NodeBootstrappingConfiguration) {
 				nbc.SecureTLSBootstrappingConfig = &datamodel.SecureTLSBootstrappingConfig{
-					Enabled:     true,
-					Deadline:    (10 * time.Second).String(),
-					AADResource: "https://management.azure.com/", // use an unexpected AAD resource to force a secure TLS bootstrapping failure
+					Enabled:                true,
+					Deadline:               (10 * time.Second).String(),
+					UserAssignedIdentityID: "invalid", // use an unexpected user-assigned identity ID to force a secure TLS bootstrapping failure
 				}
 			},
 		},