Call odrefresh in VM from composd

composd needs to prepare the directory, run a fd_server, etc. then
request to run odrefresh in the VM.

`FdServerConfig` and `FdServer` are introduced to make starting a
fd_server from composd easier.

Also, add a testing command in composd_cmd.

Bug: 205750213
Test: atest ComposHostTestCases
Test: With some local hacks in ART, with SELinux disabled in the VM,
      odrefresh completed with exit code 80 and output files that
      look normal (at least sizes are).
Change-Id: I52c9d1ad369eea6d423831adb42087a3bcf30d66
diff --git a/compos/composd/src/util.rs b/compos/composd/src/util.rs
index 091fb15..54d7751 100644
--- a/compos/composd/src/util.rs
+++ b/compos/composd/src/util.rs
@@ -18,8 +18,9 @@
 use anyhow::Result;
 use binder_common::new_binder_service_specific_error;
 use log::error;
+use std::fmt::Debug;
 
-pub fn to_binder_result<T>(result: Result<T>) -> BinderResult<T> {
+pub fn to_binder_result<T, E: Debug>(result: Result<T, E>) -> BinderResult<T> {
     result.map_err(|e| {
         let message = format!("{:?}", e);
         error!("Returning binder error: {}", &message);