Auto restart of compute instances utilizing local storage

##### ISSUE TYPE

* Feature Idea

##### COMPONENT NAME

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New feature (UI, API, etc)
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##### CLOUDSTACK VERSION

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N/A
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##### CONFIGURATION

N/A

##### OS / ENVIRONMENT

N/A

##### SUMMARY

There should be an ability to set auto boot (restart) for VMs with local storage, i.e. similar functionality as ´virsh autostart VM´ in KVM.

When a server reboot occurs, for instance if heartbeat on the host can't write to NFS share, the server will reboot. In current versions of cloudstack, all instances using local storage on that host will need to be manually started after the reboot. There should be a functionality to mark VMs to be auto started when the host is live again.

This is particularly useful when a compute instance is using local storage (SSDs) for system disk, but NFS etc. for data storage, or when not using networked attached storage but local storage only configurations.

This is functionality similar to what is requested in #8687

##### STEPS TO REPRODUCE

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Example of possible implementation:
- UI and API option for compute instance to auto boot on host startup (enable/disable feature per compute instance).
- Mgmt server to issue startup of compute instances when Host is ready.
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##### EXPECTED RESULTS

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Compute instances with local storage should be able able to auto start (if configured) when a host is live again after reboot.
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##### ACTUAL RESULTS

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Currently all local storage compute instances needs to be manually started after host reboot.
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Issue 中沒有指定任何檔案或測試。先閱讀相關 issue #8687 以及其中引用的 virsh autostart 行為，然後梳理提議的 UI/API 選項和 management-server 啟動流程；當已設定的 local-storage 執行個體能在主機重新啟動後可靠地啟動時，即視為完成。

由索引模型根據 Issue 內容生成。