(DOCSP-16851) [OM] Fix curl command bug in Add CA Certificate to Ops Manager Java Trust Store (#747)

In step 4 of the [Add CA Certificate to Ops Manager Java Trust
Store](https://www.mongodb.com/docs/ops-manager/current/tutorial/add-ca-cert-to-om/#add-ca-certificate-to-mms-java-trust-store)
page:

(1) the "cacert" option should have two leading dashes but the current
doc only has one. (meaning it should be "--cacert", instead of
"-cacert".

(2) java trust store is in JKS or PKCS12 format and cannot be accepted
as the value for the "cacert" option (which only accepts Pem) of the
curl command.

To verify bullet point (1), please use "man curl" command to check the
help doc.

To verify bullet point (2), please refer to my test attached [Test
certificate and trust
store.pdf](https://jira.mongodb.org/secure/attachment/584629/584629_Test+certificate+and+trust+store.pdf).

- [DOCS-16851](https://jira.mongodb.org/browse/DOCS-16851)
-
[STAGING](https://deploy-preview-747--docs-ops-manager.netlify.app/tutorial/add-ca-cert-to-om/)

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Author: elyse-mdb

source/includes/steps-add-ca-cert-to-om-truststore.yaml

@@ -46,11 +46,19 @@ ref: add-credentials-automation-click-credentials
 title: "Test an HTTPS request to Ops Manager to confirm connectivity."
 content: |
   
-  After adding your webhook URL to the following command,
-  run it to test your webhook's HTTPS connectivity with Ops Manager. 
+  a. Convert your Java keystore file into PEM format.
 
-  .. code-block:: sh
+     Java keystores are stored in either JKS (Java KeyStore) or PKCS12 format. These formats
+     are incompatible with the curl ``--cacert`` option.
+
+     Use a tool of your choosing, such as ``openssl``, to convert your Java keystore file.
+
+  #. Replace the placeholder text in the following command with the path to your PEM certificate
+     and your webhook URL: 
+  
+     .. code-block:: sh
 
-    sudo curl -vvvv -cacert /opt/mongodb/mms/jdk/lib/security/cacerts <WebhookURL>
+        sudo curl -vvvv --cacert </path/to/cacerts.pem> <WebhookURL>
 
+  #. Run the command to test your webhook's HTTPS connectivity with Ops Manager.
 ...