Allow structopt crate in com.android.virt apex

Also add TEST_MAPPING generated by the script.

Bug: 182570135
Test: m
Change-Id: I924ca0bce2bd134e25183a0b91ba667f4da0eefb
diff --git a/TEST_MAPPING b/TEST_MAPPING
new file mode 100644
index 0000000..0f4f93c
--- /dev/null
+++ b/TEST_MAPPING
@@ -0,0 +1,8 @@
+// Generated by update_crate_tests.py for tests that depend on this crate.
+{
+  "presubmit": [
+    {
+      "name": "authfs_device_test_src_lib"
+    }
+  ]
+}