Change AppFuse mount location to vold namespace

Previously, AppFuse is mounted in system_server's mount namespace. This
CL moves the mount location to vold namespace.

Bug: 110379912
Test: testOpenProxyFileDescriptor passes
Change-Id: Id93c26d5a98842c78f27850c83e15df619cec1ab
diff --git a/VolumeManager.h b/VolumeManager.h
index 2f76ddc..a2d6c5b 100644
--- a/VolumeManager.h
+++ b/VolumeManager.h
@@ -129,8 +129,9 @@
                          const std::string& fsLabel, std::string* outVolId);
     int destroyStubVolume(const std::string& volId);
 
-    int mountAppFuse(uid_t uid, pid_t pid, int mountId, android::base::unique_fd* device_fd);
-    int unmountAppFuse(uid_t uid, pid_t pid, int mountId);
+    int mountAppFuse(uid_t uid, int mountId, android::base::unique_fd* device_fd);
+    int unmountAppFuse(uid_t uid, int mountId);
+    int openAppFuseFile(uid_t uid, int mountId, int fileId, int flags);
 
   private:
     VolumeManager();