Add placeholder value to cortex_account_id parameter

[dms1981]

A reference to the issue / Description of it

#7607

How does this PR fix the problem?

SSM parameter requires a minimum amount of content to meet validation constraints:

Error: creating SSM Parameter (cortex_account_id): operation error SSM: PutParameter, https response error StatusCode: 400, RequestID: 895a8634-9acd-4f68-af9b-e8e5329604c8, api error ValidationException: 1 validation error detected: Value at 'value' failed to satisfy constraint: Member must have length greater than or equal to 1

How has this been tested?

Tested with local plan.

Deployment Plan / Instructions

Deploy through CI

Checklist (check x in [ ] of list items)

• I have performed a self-review of my own code
• All checks have passed
• I have made corresponding changes to the documentation
• Plan and discussed how it should be deployed to PROD (If needed)

Additional comments (if any)

{Please write here}

[github-actions]

Trivy Scan Failed

Show Output

```hcl

---

Trivy will check the following folders:
terraform/environments/core-logging

---

Running Trivy in terraform/environments/core-logging
2024-09-30T11:15:30Z INFO [db] Need to update DB
2024-09-30T11:15:30Z INFO [db] Downloading DB... repository="ghcr.io/aquasecurity/trivy-db:2"
2024-09-30T11:15:31Z FATAL Fatal error init error: DB error: failed to download vulnerability DB: database download error: oci download error: failed to fetch the layer: GET https://ghcr.io/v2/aquasecurity/trivy-db/blobs/sha256:6c84029961369564d84c3d70ad470dc3b54fdea4914bf7b14033fe85a7a50aeb: TOOMANYREQUESTS: retry-after: 146.001µs, allowed: 44000/minute
trivy_exitcode=1

</details> #### `Checkov Scan` Success
<details><summary>Show Output</summary>

```hcl

*****************************

Checkov will check the following folders:
terraform/environments/core-logging

*****************************

Running Checkov in terraform/environments/core-logging
Excluding the following checks: CKV_GIT_1,CKV_AWS_126,CKV2_AWS_38,CKV2_AWS_39
2024-09-30 11:15:34,041 [MainThread  ] [WARNI]  Failed to download module github.com/ministryofjustice/modernisation-platform-terraform-s3-bucket?ref=8688bc15a08fbf5a4f4eef9b7433c5a417df8df1:None (for external modules, the --download-external-modules flag is required)
2024-09-30 11:15:34,041 [MainThread  ] [WARNI]  Failed to download module github.com/ministryofjustice/modernisation-platform-terraform-s3-bucket?ref=cadab519b10a7d28dfa3b77d407725db6b37614a:None (for external modules, the --download-external-modules flag is required)
2024-09-30 11:15:34,041 [MainThread  ] [WARNI]  Failed to download module github.com/ministryofjustice/terraform-aws-observability-platform-tenant?ref=fbbe5c8282786bcc0a00c969fe598e14f12eea9b:None (for external modules, the --download-external-modules flag is required)
2024-09-30 11:15:34,041 [MainThread  ] [WARNI]  Failed to download module github.com/ministryofjustice/modernisation-platform-terraform-s3-bucket?ref=4e17731f72ef24b804207f55b182f49057e73ec9:None (for external modules, the --download-external-modules flag is required)
terraform scan results:

Passed checks: 377, Failed checks: 0, Skipped checks: 69


checkov_exitcode=0

CTFLint Scan Success

Show Output

*****************************

Setting default tflint config...
Running tflint --init...
Installing "terraform" plugin...
Installed "terraform" (source: github.com/terraform-linters/tflint-ruleset-terraform, version: 0.9.1)
tflint will check the following folders:
terraform/environments/core-logging

*****************************

Running tflint in terraform/environments/core-logging
Excluding the following checks: terraform_unused_declarations
tflint_exitcode=0

Trivy Scan Failed

Show Output

*****************************

Trivy will check the following folders:
terraform/environments/core-logging

*****************************

Running Trivy in terraform/environments/core-logging
2024-09-30T11:15:30Z	INFO	[db] Need to update DB
2024-09-30T11:15:30Z	INFO	[db] Downloading DB...	repository="ghcr.io/aquasecurity/trivy-db:2"
2024-09-30T11:15:31Z	FATAL	Fatal error	init error: DB error: failed to download vulnerability DB: database download error: oci download error: failed to fetch the layer: GET https://ghcr.io/v2/aquasecurity/trivy-db/blobs/sha256:6c84029961369564d84c3d70ad470dc3b54fdea4914bf7b14033fe85a7a50aeb: TOOMANYREQUESTS: retry-after: 146.001µs, allowed: 44000/minute
trivy_exitcode=1

[richgreen-moj]

lgtm