Pass unshared_obb flag to sdcardfs setup.

Bug: 110960295
Test: atest cts/hostsidetests/appsecurity/src/android/appsecurity/cts/ExternalStorageHostTest.java
Change-Id: I945722849ce225ca701bba482c859f1a6567bb63
diff --git a/model/EmulatedVolume.cpp b/model/EmulatedVolume.cpp
index 1d5546c..73bf6d1 100644
--- a/model/EmulatedVolume.cpp
+++ b/model/EmulatedVolume.cpp
@@ -91,6 +91,7 @@
                 "-w",
                 "-G",
                 "-i",
+                "-o",
                 mRawPath.c_str(),
                 label.c_str(),
                 NULL)) {