Unable to assign ISO permissions to Account in sub-Domain

##### ISSUE TYPE

* Bug Report

##### COMPONENT NAME

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UI, ISOs/Templates
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##### CLOUDSTACK VERSION

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4.19.0.2
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##### CONFIGURATION

N/A

##### OS / ENVIRONMENT

N/A

##### SUMMARY

When attempting to share access of an ISO or template to an account in a sub-domain, an error is raised about "Unable to grant a launch permission to account ', account not found."

This creates two problems:
1. There is no way to effectively share an ISO or template from a parent domain to a sub-domain, which can lead to duplicate ISOs or templates required for each sub-domain. Sharing the templates or ISOs publicly is not desired in a multi-tenant cloud service provider environment.
2. Setting `share.public.templates.with.other.domains` to false permits a parent domain to create a public template only visible to that domain. The account in the parent domain can then assign an instance created with said template or ISO to an account in a sub-domain. The issue is, the template or ISO is not visible for provisioning new instances within the account of the sub-domain.

##### STEPS TO REPRODUCE

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1. Have a domain with at least one sub-domain.
2. Have an account created in each of these domains.
3. Create a non-public ISO or template in the parent domain.
4. Select "Update Template Permissions" from the template window.
5. Select "Share With: Account".
6. Select the account in the sub-Domain.
~~~

##### EXPECTED RESULTS

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The account in the sub-domain is able to access the ISO or template.
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##### ACTUAL RESULTS

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Error below is recevied.
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