fix: INTMDB-1163 Changed create only properties

[Adelmar92]

Proposed changes

Problem

in this issue #745 the user is trying to update the Mappings property.

Reading the SearchIndex documentation i see that Mappings is marked as Update requires: No interruption

this means that if the user modifies this property, cloud formation should only execute the update, but reading the cloud formation template the Mapping property is marked as CreateOnly, (CreateOnly properties remplaces the resource when updated)

so when the user is trying to update this property, the resource gets replaced even tho the docs show otherwise.

Solution

This got solved by removing the properties that are not read only.

Jira ticket: INTMDB-1163

Type of change:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as
  expected)
• This change requires a documentation update

Manual QA performed:

• cfn invoke for each of CRUDL/cfn test
• Updated resource in example
• Published to AWS private registry
• Used the template in example to create and update a stack in AWS
• Deleted stack to ensure resources are deleted
• Created multiple resources in same stack
• Validated in Atlas UI
• Included screenshots

Required Checklist:

• I have signed the MongoDB CLA
• I have added tests that prove my fix is effective or that my feature works
• I have added any necessary documentation (if appropriate)
• I have run make fmt and formatted my code
• For CFN Resources: I have released by changes in the private registry and proved by change
  works in Atlas

Further comments