Update custom-endpoint-aliases.md (elastic#2117)

Update wording to match ECH portal text. 

Current customer-facing wording:
<img width="647" height="133" alt="image"
src="https://github.com/user-attachments/assets/da5125e6-1c31-472a-ae97-7656a7d15531"
/>

Author: mmahacek

deploy-manage/deploy/elastic-cloud/custom-endpoint-aliases.md

@@ -32,7 +32,7 @@ New deployments are assigned a default alias derived from the deployment name. T
 To add an alias to an existing deployment:
 
 1. From the **Hosted deployments** menu, select a deployment.
-2. Under **Custom endpoint alias**, select **Edit**.
+2. Under **Connection alias**, select **Create an alias**.
 3. Define a new alias. Make sure you choose something meaningful to you.
 
     ::::{tip}
@@ -47,8 +47,8 @@ To add an alias to an existing deployment:
 To remove an alias from your deployment, or if you want to re-assign an alias to another deployment, follow these steps:
 
 1. From the **Hosted deployments** menu, select a deployment.
-2. Under **Custom endpoint alias**, select **Edit**.
-3. Remove the text from the **Custom endpoint alias** text box.
+2. Under *Connection alias**, select **Edit**.
+3. Remove the text from the **Connection alias** text box.
 4. Select **Update alias**.
 
 ::::{note}