vold: Support aborting FUSE connections.

This can be done through binder as well as vdc, using 'vdc volume
abort_fuse'.

Bug: 153411204
Test: adb shell vdc volume abort_fuse
Change-Id: I93e46dc1cd361729cc1162c63520cf73152ea409
diff --git a/Utils.h b/Utils.h
index eac3cf4..c4926e7 100644
--- a/Utils.h
+++ b/Utils.h
@@ -50,6 +50,8 @@
 status_t CreateDeviceNode(const std::string& path, dev_t dev);
 status_t DestroyDeviceNode(const std::string& path);
 
+status_t AbortFuseConnections();
+
 int SetQuotaInherit(const std::string& path);
 int SetQuotaProjectId(const std::string& path, long projectId);
 /*