Assorted refactoring

Mostly removing duplication. Also added a comment as suggested by
Andrew.

Bug: 161471326
Test: composd_cmd async-odrefresh

Change-Id: I7da83cb825de7b4fd2267b1e496808a423544c16
diff --git a/compos/common/Android.bp b/compos/common/Android.bp
index 7c61d94..39e7c0a 100644
--- a/compos/common/Android.bp
+++ b/compos/common/Android.bp
@@ -11,6 +11,7 @@
         "android.system.virtualizationservice-rust",
         "compos_aidl_interface-rust",
         "libanyhow",
+        "libbinder_common",
         "libbinder_rpc_unstable_bindgen",
         "libbinder_rs",
         "liblog_rust",