Update to use an Amazon Linux 2 image - WISCALERTS-2

• In order to increase disk space allocated for Docker container utilize Amazon Linux 2. By default Amazon Linux 2 uses overlay2 storage driver, which gives the base storage size of the space left on the disk.
• Removed SSM agent as it's shipped with all Amazon Linux 2 AMIs.
• Utilized SSM param store for storing IICS user credentials.
• Increased EBS volume size to allocate more disk space.

@JARED.KOSANOVIC @ERIC.SCHOVILLE @jont

terraform/templates/container-definitions.tpl

@@ -18,21 +18,21 @@
         "hostPort": ${app_port3}
       }
     ],
-    "environment": [
-        {
-            "name": "INFORMATICA_USER",
-            "value": "${informatica_username}"
-        },
-        {
-            "name": "INFORMATICA_PASSWORD",
-            "value": "${informatica_password}"
-        }
-    ],
     "mountPoints": [
         {
             "containerPath": "${secure_agent_mount_path}",
             "sourceVolume": "agent-configs-path"
         }
+    ],
+    "secrets":[
+        {
+            "name":"INFORMATICA_USER",
+            "valueFrom":"${informatica_username}"
+        },
+        {
+            "name":"INFORMATICA_PASSWORD",
+            "valueFrom":"${informatica_password}"
+        }
     ]
   }
 ]
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