Add context mount option for appfuse.

BUG=26147865

Change-Id: I1812c46d0f80eaea9a9a3fa944bc4d0126ae8ba1
diff --git a/CommandListener.cpp b/CommandListener.cpp
index 8808065..863724b 100644
--- a/CommandListener.cpp
+++ b/CommandListener.cpp
@@ -651,7 +651,9 @@
             "rootmode=40000,"
             "default_permissions,"
             "allow_other,"
-            "user_id=%d,group_id=%d",
+            "user_id=%d,group_id=%d,"
+            "context=\"u:object_r:app_fuse_file:s0\","
+            "fscontext=u:object_r:app_fusefs:s0",
             device_fd,
             uid,
             uid);