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: I91e1a4124163fba65e4cc673f4b7cefc9cce45fa
diff --git a/patches/Android.bp.patch b/patches/Android.bp.patch
new file mode 100644
index 0000000..c80e275
--- /dev/null
+++ b/patches/Android.bp.patch
@@ -0,0 +1,15 @@
+diff --git a/Android.bp b/Android.bp
+index b9fd260..103ae9b 100644
+--- a/Android.bp
++++ b/Android.bp
+@@ -16,6 +16,10 @@ rust_library {
+         ":copy_proc-macro-nested_build_out",
+     ],
+     edition: "2015",
++    apex_available: [
++        "//apex_available:platform",
++        "com.android.virt",
++    ],
+ }
+ 
+ rust_defaults {