Add os parameter to composd_cmd

This will be used by AVFHostTestCases and ComposTestCases to test
various microdroid OSes.

Bug: 302465542
Test: composd_cmd
Change-Id: I85b86fa66f0c79b633eb359873b94edcff79d561
diff --git a/android/compos_verify/verify.rs b/android/compos_verify/verify.rs
index a3f18d5..b94ebbc 100644
--- a/android/compos_verify/verify.rs
+++ b/android/compos_verify/verify.rs
@@ -124,6 +124,7 @@
         &idsig_manifest_ext_apk,
         &VmParameters {
             name: String::from("ComposVerify"),
+            os: String::from("microdroid"),
             cpu_topology: VmCpuTopology::OneCpu, // This VM runs very little work at boot
             debug_mode: args.debug,
             ..Default::default()