Update wording for FileVault policy (#15093)

The original text implies that FileVault can be enabled with the policy
query. Updated wording to clarify.

articles/zero-trust-attestation-with-fleet.md

@@ -23,7 +23,7 @@ Fleet allows security teams to write policies that reflect the company's access
 
 ![Create a policy modal in Fleet](../website/assets/images/articles/create-a-new-policy-800x450@2x.jpg)
 
-For example, many organizations need to encrypt their devices’ hard disks. In Fleet, this can be accomplished with the following policy:
+For example, many organizations need to encrypt their devices’ hard disks. In Fleet, you can verify that FileVault is enabled with the following policy:
 
 ```
 SELECT 1 
@@ -95,4 +95,4 @@ For any questions about setting up zero trust at your organization, you can [tal
 <meta name="authorGitHubUsername" value="zhumo">
 <meta name="category" value="guides">
 <meta name="publishedOn" value="2022-10-14">
-<meta name="articleImageUrl" value="../website/assets/images/articles/fleet-for-zero-trust-attestation-800x450@2x.jpg">
+<meta name="articleImageUrl" value="../website/assets/images/articles/fleet-for-zero-trust-attestation-800x450@2x.jpg">