Handle case where gsi_fstab is empty string
am: 9f619b5904

Change-Id: I64712ceeb071ccb8758863c5591f8207401a12f9
diff --git a/host/libs/vm_manager/crosvm_manager.cpp b/host/libs/vm_manager/crosvm_manager.cpp
index 2241b0e..a3b9082 100644
--- a/host/libs/vm_manager/crosvm_manager.cpp
+++ b/host/libs/vm_manager/crosvm_manager.cpp
@@ -82,7 +82,9 @@
   command.AddParameter("--rwdisk=", config_->vendor_image_path());
   command.AddParameter("--rwdisk=", config_->product_image_path());
   command.AddParameter("--socket=", GetControlSocketPath(config_));
-  command.AddParameter("--android-fstab=", config_->gsi_fstab_path());
+  if (!config_->gsi_fstab_path().empty()) {
+    command.AddParameter("--android-fstab=", config_->gsi_fstab_path());
+  }
   command.AddParameter("--single-touch=", config_->touch_socket_path(), ":",
                        config_->x_res(), ":", config_->y_res());
   command.AddParameter("--keyboard=", config_->keyboard_socket_path());