virtmgr: Add "--skip-pivot-root" option

"--skip-pivot-root" allows crosvm vhost-user-fs backend
without pivot_root and mount namespace.

Bug: 372171883
Test: Launch Terminal app with virtiofs enabled
Change-Id: Ic20247f1d5d4a2392eabe8bd260238c2f73e764f
Signed-off-by: Akilesh Kailash <akailash@google.com>
diff --git a/android/virtmgr/src/crosvm.rs b/android/virtmgr/src/crosvm.rs
index 86b3571..707f285 100644
--- a/android/virtmgr/src/crosvm.rs
+++ b/android/virtmgr/src/crosvm.rs
@@ -920,7 +920,8 @@
             .arg(format!("--shared-dir={}", &shared_path.path))
             .arg("--cfg")
             .arg(cfg_arg.as_str())
-            .arg("--disable-sandbox");
+            .arg("--disable-sandbox")
+            .arg("--skip-pivot-root=true");
 
         print_crosvm_args(&command);