Build composd with avf flags

We uniformly want to have all targets within virtualization/ built with
AVF flags.

composd need to use `llpvm_changes` flag to determine whether to
persist or use instance_id or not.

Test: Builds
Bug: 291213394
Change-Id: Ia4d935ee0559e83e9213eccf216285114c7cfdf0

compos/composd/Android.bp

diff --git a/compos/composd/Android.bp b/compos/composd/Android.bp
index b0294dd..75f0c4f 100644
--- a/compos/composd/Android.bp
+++ b/compos/composd/Android.bp
@@ -7,6 +7,7 @@
     srcs: ["src/composd_main.rs"],
     edition: "2021",
     prefer_rlib: true,
+    defaults: ["avf_build_flags_rust"],
     rustlibs: [
         "android.system.composd-rust",
         "android.system.virtualizationservice-rust",