Add an EFS volume into Secure Agent infrastructure

This volume will act as the persistence storage for Secure Agent's logs and configurations. Note that Fargate in ECS doesn't support EFS volume, so had to use EC2+linux template for ECS.

@bhill6 @JARED.KOSANOVIC @ERIC.SCHOVILLE

terraform/templates/container.tpl

@@ -2,8 +2,6 @@
   {
     "name": "${container_name}",
     "image": "${image_name}",
-    "cpu": ${fargate_cpu},
-    "memory": ${fargate_memory},
     "networkMode": "${network_mode}",
     "portMappings": [
       {