Updating alarms feed params does not change scheduled trigger execution

In the manifest.yml file, you can specify schedule cron jobs with trigger feeds and rules.

```yaml
actions:
import-users:
function: actions/import-user/index.js
runtime: 'nodejs:12'
triggers:
sync-users:
feed: /whisk.system/alarms/interval
inputs:
minutes: 1
rules:
sync-users-rule:
trigger: sync-users
action: import-users
```

After that you might want to update the interval to be 3 minutes instead of 1. Then `aio app deploy`. After redeployed you can check the info of `sync-users` trigger. It shows 3 minutes correctly.

```bash
{
"annotations": [
{
"key": "whisk-managed",
"value": {
...
}
},
{
"key": "feed",
"value": "/whisk.system/alarms/interval"
}
],
"limits": {},
"name": "sync-users",
"namespace": "my-namespace",
"parameters": [
{
"key": "minutes",
"value": 3
}
],
"publish": false,
"rules": {
"my-namespace/sync-users-rule": {
"action": {
"name": "import-users",
"path": "my-namespace/test-app-alarms-0.0.1"
},
"status": "active"
}
},
"updated": 1605187489818,
"version": "0.0.6"
}
```

However the trigger is still fired every minute, like it was never updated.

This could be an issue with the alarms package itself, but creating this ticket for triaging purpose.

manifest.yml の例の動作を、`aio app deploy` でデプロイして再現し、その後 trigger 情報と alarms パッケージの動作を調査します。報告された間隔と実際の発火頻度を比較します。完了条件は、feed パラメーターを更新するとスケジュールされた実行間隔が変わること、または外部の alarms コンポーネントが原因であることを明確に特定できることです。

索引モデルが issue の本文から書いたものです。