Add Global Setting for Start Instance Default

Add Global Setting for Start Instance Default

##### ISSUE TYPE

* Enhancement Request

##### COMPONENT NAME

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UI
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##### CLOUDSTACK VERSION

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4.19.1.1
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##### CONFIGURATION

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N/A
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##### OS / ENVIRONMENT

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KVM
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##### SUMMARY

We would like to change the default behavior at instance creation for some use cases we have. This Enhancement would add the ability to change that behavior if someone wanted to. A global setting would accomplish this and let the default out of the box still be Start by default.

##### STEPS TO REPRODUCE

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N/A - Workflow Enhancement
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##### EXPECTED RESULTS

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Global Setting that would change the default behavior of Start Instance from `Yes` to `No`. The Global setting would be set to `Yes` by default.
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##### ACTUAL RESULTS

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Default is hard coded to Start Instance at instance creation.
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Start by locating the instance-creation path and the existing global-setting definitions; the issue does not name specific files or tests. Done means a global setting defaults to Yes, allows changing the default Start Instance behavior to No, and preserves the current out-of-the-box behavior when unchanged.

Written by the indexing model from the issue text.