[ResponseOps] SSL settings misconfiguration (#239972)

Resolves elastic/response-ops-team#451

## Summary

This PR updates `getSSLSettingsFromConfig` to return a stricter
`verificationMode` by default.


### Checklist

- [ ] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios

Author: doakalexi

x-pack/platform/plugins/shared/actions/server/lib/get_node_ssl_options.test.ts

@@ -181,4 +181,11 @@ describe('getSSLSettingsFromConfig', () => {
       verificationMode: 'certificate',
     });
   });
+
+  test('get verificationMode eql "full", if both values eql undefined', () => {
+    const nodeOption = getSSLSettingsFromConfig(undefined, undefined);
+    expect(nodeOption).toMatchObject({
+      verificationMode: 'full',
+    });
+  });
 });

x-pack/platform/plugins/shared/actions/server/lib/get_node_ssl_options.ts

@@ -73,5 +73,5 @@ export function getSSLSettingsFromConfig(
   } else if (rejectUnauthorized !== undefined) {
     return { verificationMode: rejectUnauthorized ? 'full' : 'none' };
   }
-  return {};
+  return { verificationMode: 'full' };
 }

x-pack/platform/plugins/shared/stack_connectors/server/connector_types/email/send_email.test.ts

@@ -804,7 +804,7 @@ describe('send_email module', () => {
           "secure": false,
           "tls": Object {
             "ca": "ca cert data goes here",
-            "rejectUnauthorized": false,
+            "rejectUnauthorized": true,
           },
         },
       ]
@@ -851,7 +851,7 @@ describe('send_email module', () => {
           "secure": false,
           "tls": Object {
             "ca": "ca cert data goes here",
-            "rejectUnauthorized": false,
+            "rejectUnauthorized": true,
           },
         },
       ]
@@ -901,6 +901,7 @@ describe('send_email module', () => {
           "secure": false,
           "tls": Object {
             "ca": "ca cert data goes here",
+            "rejectUnauthorized": true,
           },
         },
       ]