Expand documentation on selinux_android_tee_service_context_handle

Bug: 380300152
Test: presubmit
Change-Id: I9c85dd43d2ee3921f37cebd82cf760518338aad2
diff --git a/libselinux/include/selinux/android.h b/libselinux/include/selinux/android.h
index f7050ca..8c3d6d4 100644
--- a/libselinux/include/selinux/android.h
+++ b/libselinux/include/selinux/android.h
@@ -26,7 +26,10 @@
 /* Returns the keystore2 context handle */
 extern struct selabel_handle* selinux_android_keystore2_key_context_handle(void);
 
-/* Returns the tee_service context handle */
+/* Returns the tee_service context handle.
+ * These handle can be used as a paramter of selabel_lookup function to resolve
+ * the provided trusted execution environment (tee) service to the corresponding
+ * selinux context. */
 extern struct selabel_handle* selinux_android_tee_service_context_handle(void);
 
 /* Sets the file context handle. Must be called using the output of