[BUG][Functional] Adding a second CIDR to a VPC doesn't create a blackhole in the segregated TGW route for the second CIDR

[jblaplace]

Bug reports which fail to provide the required information will be closed without action.

Required Basic Info

• Accelerator Version: 1.5.0
• Install Type: Clean
• Upgrade from version: N/A

Describe the bug
We added a second CIDR block to a shared VPC and created new subnets out of that CIDR block.
SM ran fine, CIDR block was added to VPC, subnets were created as expected. All 'propagated' routes in the TGW RT had routes to the new CIDR range BUT the segregated route table only shows a static black hole for the first CIDR block. There is no blackhole for the second CIDR block. This is a security issue where you could have inter shared_vpc communications (ie: dev talks to prod vpc).

Failure Info

• What error messages have you identified, if any: N/A
• What symptoms have you identified, if any: No blackhole in the segregated RT that covers the new CIDR block.

Required files

• Please provide a copy of your config.json file (sanitize if required)

Steps To Reproduce

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2. Click on '....'
3. See error

Expected behavior
A clear and concise description of what you expected to happen.
A new Static Blackhole should be created that covers the new CIDR range.

Screenshots
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Additional context
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