Extract a library for common CompOS things

A small refactoring as a preliminary step to creating composd.

Create a Rust library for useful things shared by various
CompOS-related binaries. This initially includes the code to start the
VM and connect to CompOS, as well as various useful constants.

As part of extracting the start VM code I migrated to using logging
directly rather than writing to stdout/stderr for greater reusability,
as suggested by Victor.

Bug: 186126194
Test: Get odsign to run compos_verify_key, still works
Change-Id: I57b7ebcdd1a6cb604b5d739b8a8e028fd59e7b90
diff --git a/compos/verify_key/Android.bp b/compos/verify_key/Android.bp
index dd54f76..a5892b8 100644
--- a/compos/verify_key/Android.bp
+++ b/compos/verify_key/Android.bp
@@ -5,18 +5,17 @@
 rust_binary {
     name: "compos_verify_key",
     srcs: ["verify_key.rs"],
+    edition: "2018",
     rustlibs: [
-        "android.system.virtualizationservice-rust",
         "compos_aidl_interface-rust",
+        "libandroid_logger",
         "libanyhow",
-        "libbinder_rpc_unstable_bindgen",
         "libbinder_rs",
         "libclap",
+        "libcompos_common",
+        "liblog_rust",
     ],
     prefer_rlib: true,
-    shared_libs: [
-        "libbinder_rpc_unstable",
-    ],
     apex_available: [
         "com.android.compos",
     ],