Trying to define multiple receivers in a single user-defined AlertmanagerConfig

always   

#### Monitoring for user-defined projects is enabled
```
oc -n openshift-monitoring get configmap cluster-monitoring-config -o yaml | head -4
```
```
apiVersion: v1
data:
  config.yaml: |
    enableUserWorkload: true
```

#### separate Alertmanager instance for user-defined alert routing is Enabled and Configured
```
oc -n openshift-user-workload-monitoring get configmap user-workload-monitoring-config -o yaml | head -6
```
```
apiVersion: v1
data:
  config.yaml: |
    alertmanager:
      enabled: true
      enableAlertmanagerConfig: true
```
create testing namespace 
oc new-project libor-alertmanager-testing 
```
## TESTING - MULTIPLE RECEIVERS IN ALERTMANAGERCONFIG
Single AlertmanagerConfig
`alertmanager_config_webhook_and_email_rootDefault.yaml`
```
apiVersion: monitoring.coreos.com/v1beta1
kind: AlertmanagerConfig
metadata:
  name: libor-alertmanager-testing-email-webhook
  namespace: libor-alertmanager-testing
spec:
  receivers:
  - name: 'libor-alertmanager-testing-webhook'
    webhookConfigs:
      - url: 'http://prometheus-msteams.internal-monitoring.svc:2000/occ-alerts'
  - name: 'libor-alertmanager-testing-email'
    emailConfigs:
      - to: USER@USER.CO
        requireTLS: false
        sendResolved: true
  - name: Default
  route:
    groupBy:
    - namespace
    receiver: Default
    groupInterval: 60s
    groupWait: 60s
    repeatInterval: 12h
    routes:
    - matchers:
      - name: severity
        value: critical
        matchType: '='
        continue: true
      receiver: 'libor-alertmanager-testing-webhook'
    - matchers:
      - name: severity
        value: critical
        matchType: '='
      receiver: 'libor-alertmanager-testing-email'
```
Once saved the continue statement is removed from the object. 
```
the configuration applied to alertmanager contains continue false statements
```
oc exec -n openshift-user-workload-monitoring alertmanager-user-workload-0 -- amtool config show --alertmanager.url http://localhost:9093 

```
route:
  receiver: Default
  group_by:
  - namespace
  continue: false
  routes:
  - receiver: libor-alertmanager-testing/libor-alertmanager-testing-email-webhook/Default
    group_by:
    - namespace
    matchers:
    - namespace="libor-alertmanager-testing"
    continue: true
    routes:
    - receiver: libor-alertmanager-testing/libor-alertmanager-testing-email-webhook/libor-alertmanager-testing-webhook
      matchers:
      - severity="critical"
      continue: false  <----
    - receiver: libor-alertmanager-testing/libor-alertmanager-testing-email-webhook/libor-alertmanager-testing-email
      matchers:
      - severity="critical"
      continue: false <-----
```
If I update the statements to read `continue: true` 
and test here: https://prometheus.io/webtools/alerting/routing-tree-editor/ 

then I get the desired results

workaround is to use 2 separate files - the continue statement is being added. 

Once saved the continue statement is removed from the object. 

continue true statement is retain and applied to alertmanager