CDD: Updated VPN disclosure requirements for privacy

The AOSP implementation of Android 8.0, have made improvements to the
VPN user interface in order to better emphasize the risk differences
between VPNs and root CAs by making the VPN user interface of the
warning explicit as to what is happening.

Bug: 36031671
Test: N/A
Change-Id: I50bf21e18fe893fa8deeb741096fde1ff66e8cdf

diff --git a/9_security-model/9_8_privacy.md b/9_security-model/9_8_privacy.md
index a154175..dab621c 100644
--- a/9_security-model/9_8_privacy.md
+++ b/9_security-model/9_8_privacy.md

@@ -19,9 +19,15 @@
 CA store as [provided](https://source.android.com/security/overview/app-security.html#certificate-authorities)
 in the upstream Android Open Source Project.
 
-When devices are routed through a VPN, or a user root CA is installed, the
-implementation MUST display a warning indicating the network traffic may be
-monitored to the user.
+When device traffic is routed through a VPN, the implementation MUST display a
+warning to the user indicating either:
+
+   * That network traffic may be monitored.
+   * That network traffic is being routed through the specific VPN application
+     providing the VPN.
+
+When a user root CA is installed the implementation MUST display a warning
+indicating the network traffic may be monitored to the user.
 
 If a device implementation has a USB port with USB peripheral mode support, it
 MUST present a user interface asking for the user's consent before allowing