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.

通过使用 `aio app deploy` 部署来复现 manifest.yml 示例中的行为，然后检查 trigger 信息和 alarms 包的行为。将报告的间隔与实际触发频率进行比较；当更新 feed 参数会改变计划的执行间隔，或能明确识别负责此问题的外部 alarms 组件时，即表示完成。

由索引模型根据 Issue 内容生成。