Make ErrorCode an enum

Change the VS AIDL to define it as an enum. Added a new common AIDL
module to hold it, since this is needed by both existing AIDLs, and we
don't want either directly depending on the other.

Modify vmclient to also have Rust enum for ErrorCode, with translation
logic, in the same way as we did for DeathReason. Switch to Debug
rather than Display for these enums.

Also fixed a couple of AIDL warnings (enum-explicit-default).

We also need translation in the Java API, but I'll do that as part of
https://r.android.com/2192077.

Bug: 236811123
Test: atest MicrodroidTests MicrodroidHostTestCases
Test: composd_cmd test-compile
Change-Id: I561e5f43f0f1c74d1318dc41782ed390bb5f0337
diff --git a/vmclient/Android.bp b/vmclient/Android.bp
index 213125e..88b0c9a 100644
--- a/vmclient/Android.bp
+++ b/vmclient/Android.bp
@@ -8,6 +8,7 @@
     srcs: ["src/lib.rs"],
     edition: "2021",
     rustlibs: [
+        "android.system.virtualizationcommon-rust",
         "android.system.virtualizationservice-rust",
         "libbinder_rs",
         "liblog_rust",