add crosvm to com.android.virt

To do so, crosvm and its dependencies have the apex_available property
set to "//apex_available:platform", "com.android.virt" to explicitly
acknowledge the joining.

Bug: 174639241
Test: m com.android.virt
Change-Id: Id4bd6439bca52502e48e22082603ba64703e0d4e
diff --git a/Android.bp b/Android.bp
index f99592b..90fd1da 100644
--- a/Android.bp
+++ b/Android.bp
@@ -1,4 +1,4 @@
-// This file is generated by cargo2android.py --run --dependencies --features=bytes --device --copy-out.
+// This file is generated by cargo2android.py --run --dependencies --device --features=bytes --copy-out --patch=patches/Android.bp.patch.
 
 genrule {
     name: "copy_protobuf_build_out",
@@ -20,6 +20,10 @@
     rustlibs: [
         "libbytes",
     ],
+    apex_available: [
+        "//apex_available:platform",
+        "com.android.virt",
+    ],
 }
 
 // dependent_library ["feature_list"]