Add authfs and fd_server to com.android.virt apex

Note that authfs is added to the "direct" apex image temporarily (instead
of microdroid) to unblock integration test within Android.  Once binder
across the VM boundary is supported and authfs is updated, it should be
moved to microdroid.

Bug: 182570135
Test: TARGET_BUILD_APPS=com.android.virt m
Test: Use in integration test
Change-Id: I1fac1090ab33cc1a082fe594aa07c9f811576b55
diff --git a/authfs/Android.bp b/authfs/Android.bp
index 9f7be93..4a20a0c 100644
--- a/authfs/Android.bp
+++ b/authfs/Android.bp
@@ -39,11 +39,13 @@
     ],
     bindgen_flags: ["--size_t-is-usize"],
     cflags: ["-D BORINGSSL_NO_CXX"],
+    apex_available: ["com.android.virt"],
 }
 
 rust_binary {
     name: "authfs",
     defaults: ["authfs_defaults"],
+    apex_available: ["com.android.virt"],
 }
 
 rust_test {