Make KMS alias unique

[dms1981]

A reference to the issue / Description of it

#7607

How does this PR fix the problem?

Makes KMS alias unique in case module is called more than once

How has this been tested?

Tested with local plan

Deployment Plan / Instructions

Run deployments against core-vpc and core-network-services against main branch once PR has been merged in

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 Success

Show Output

```hcl

---

Trivy will check the following folders:
terraform/modules/cloudwatch-firehose

---

Running Trivy in terraform/modules/cloudwatch-firehose
2024-08-23T12:21:25Z INFO [db] Need to update DB
2024-08-23T12:21:25Z INFO [db] Downloading DB... repository="ghcr.io/aquasecurity/trivy-db:2"
2024-08-23T12:21:27Z INFO [vuln] Vulnerability scanning is enabled
2024-08-23T12:21:27Z INFO [misconfig] Misconfiguration scanning is enabled
2024-08-23T12:21:27Z INFO Need to update the built-in policies
2024-08-23T12:21:27Z INFO Downloading the built-in policies...
74.86 KiB / 74.86 KiB [-----------------------------------------------------------] 100.00% ? p/s 0s2024-08-23T12:21:27Z INFO [secret] Secret scanning is enabled
2024-08-23T12:21:27Z INFO [secret] If your scanning is slow, please try '--scanners vuln' to disable secret scanning
2024-08-23T12:21:27Z INFO [secret] Please see also https://aquasecurity.github.io/trivy/v0.54/docs/scanner/secret#recommendation for faster secret detection
2024-08-23T12:21:28Z INFO Number of language-specific files num=0
2024-08-23T12:21:28Z INFO Detected config files num=3
trivy_exitcode=0

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

```hcl

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

Checkov will check the following folders:
terraform/modules/cloudwatch-firehose

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

Running Checkov in terraform/modules/cloudwatch-firehose
Excluding the following checks: CKV_GIT_1,CKV_AWS_126,CKV2_AWS_38,CKV2_AWS_39
terraform scan results:

Passed checks: 74, Failed checks: 0, Skipped checks: 6


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: 0.5.0)
tflint will check the following folders:
terraform/modules/cloudwatch-firehose

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

Running tflint in terraform/modules/cloudwatch-firehose
Excluding the following checks: terraform_unused_declarations
tflint_exitcode=0

Trivy Scan Success

Show Output

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

Trivy will check the following folders:
terraform/modules/cloudwatch-firehose

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

Running Trivy in terraform/modules/cloudwatch-firehose
2024-08-23T12:21:25Z	INFO	[db] Need to update DB
2024-08-23T12:21:25Z	INFO	[db] Downloading DB...	repository="ghcr.io/aquasecurity/trivy-db:2"
2024-08-23T12:21:27Z	INFO	[vuln] Vulnerability scanning is enabled
2024-08-23T12:21:27Z	INFO	[misconfig] Misconfiguration scanning is enabled
2024-08-23T12:21:27Z	INFO	Need to update the built-in policies
2024-08-23T12:21:27Z	INFO	Downloading the built-in policies...
74.86 KiB / 74.86 KiB [-----------------------------------------------------------] 100.00% ? p/s 0s2024-08-23T12:21:27Z	INFO	[secret] Secret scanning is enabled
2024-08-23T12:21:27Z	INFO	[secret] If your scanning is slow, please try '--scanners vuln' to disable secret scanning
2024-08-23T12:21:27Z	INFO	[secret] Please see also https://aquasecurity.github.io/trivy/v0.54/docs/scanner/secret#recommendation for faster secret detection
2024-08-23T12:21:28Z	INFO	Number of language-specific files	num=0
2024-08-23T12:21:28Z	INFO	Detected config files	num=3
trivy_exitcode=0