Add Drupal 10.2 notes to Drupal and Browser monitoring

src/content/docs/apm/agents/php-agent/features/browser-monitoring-php-agent.mdx

@@ -111,6 +111,13 @@ Here are some basic examples.
        <Callout variant="important">
          In Drupal 7.15, <DoNotTranslate>**Compress cached pages**</DoNotTranslate> is turned on by default. If you also select <DoNotTranslate>**Cache pages for anonymous users**</DoNotTranslate>, the JavaScript (newrelic.js) is not inserted into the served pages for anonymous users. This is because Drupal's pages are compressed directly from the database before they are stored in the cache (with gzip), so New Relic's PHP agent does not have a chance to parse any HTML. In this situation, manual instrumentation provides a better opportunity to capture data for anonymous users.
        </Callout>
+
+       <Callout variant="important">
+	Drupal 10.2 introduced a [new change](https://www.drupal.org/node/3298551) which causes it to set a `content-length` header.
+	New Relic PHP agent is unable to auto-inject the browser auto-instrumentation when the HTTP header field `Content-Length` is set.
+	To keep using browser monitoring, disable browser auto-instrumentation and manually insert the JavaScript header and footer into your templates.
+       </Callout>
+
   </Collapser>
 </CollapserGroup>