Updates Vault Instance Types in GovCloud

See https://github.xdr.accenturefederalcyber.com/mdr-engineering/msoc-infrastructure/pull/1247 for more info.

prod/aws-us-gov/mdr-prod-c2/account.hcl

@@ -191,7 +191,7 @@ locals {
   resolver_instance_type = "t3a.micro"
 
   # Vault Server
-  vault_server_instance_type = "t3a.micro"
+  vault_server_instance_type = "t3a.medium"
   
   # Sensu Server
   sensu_server_instance_type = "t3a.medium"

test/aws-us-gov/mdr-test-c2/account.hcl

@@ -192,7 +192,7 @@ locals {
   repo_server_instance_type = "t3a.micro"
 
   # Vault Server
-  vault_server_instance_type = "t3a.micro"
+  vault_server_instance_type = "t3a.small"
 
   # Sensu Server
   sensu_server_instance_type = "t3a.medium"