Keystore 2.0: Add wifi namespace to sepolicy.

Add the wifi namespace to sepolicy and allow system_app (Settings) and
wifi_supplicant to manage/use the keys in that namespace

Test: N/A
Bug: 171305388
Change-Id: Ib6af8656b18288a1116c241c2e76d9aea421a889
diff --git a/private/system_app.te b/private/system_app.te
index 4284835..f9d3c1c 100644
--- a/private/system_app.te
+++ b/private/system_app.te
@@ -142,6 +142,16 @@
     use
 };
 
+# Allow Settings to manage WI-FI keys.
+allow system_app wifi_key:keystore2_key {
+    delete
+    get_info
+    grant
+    rebind
+    update
+    use
+};
+
 # settings app reads /proc/version
 allow system_app {
   proc_version