Don't set dalvik.vm.boot-dex2oat-threads inside VM

dex2oat by default uses all available CPUs. So as long as the number of
vCPU follows the system property (in the host), we are fine.

Bug: 197358423
Test: m
Change-Id: I77874a84b46a9db4797f4531776718a281d33202
diff --git a/compos/Android.bp b/compos/Android.bp
index ae0c4c3..401f1c7 100644
--- a/compos/Android.bp
+++ b/compos/Android.bp
@@ -30,7 +30,6 @@
         "libprotobuf",
         "libregex",
         "libring",
-        "librustutils",
         "libscopeguard",
     ],
     prefer_rlib: true,
diff --git a/compos/src/compsvc.rs b/compos/src/compsvc.rs
index 0150f3c..28bf5d9 100644
--- a/compos/src/compsvc.rs
+++ b/compos/src/compsvc.rs
@@ -21,7 +21,6 @@
 use anyhow::{Context, Result};
 use binder_common::new_binder_exception;
 use compos_common::binder::to_binder_result;
-use compos_common::DEX2OAT_THREADS_PROP_NAME;
 use log::warn;
 use std::default::Default;
 use std::path::PathBuf;
@@ -42,7 +41,6 @@
     BinderFeatures, ExceptionCode, Interface, Result as BinderResult, Strong,
 };
 use compos_common::odrefresh::ODREFRESH_PATH;
-use rustutils::system_properties;
 
 const AUTHFS_SERVICE_NAME: &str = "authfs_service";
 const DEX2OAT_PATH: &str = "/apex/com.android.art/bin/dex2oat64";
@@ -134,10 +132,6 @@
         fd_annotation: &FdAnnotation,
     ) -> BinderResult<CompilationResult> {
         let authfs_service = get_authfs_service()?;
-        to_binder_result(
-            system_properties::write(DEX2OAT_THREADS_PROP_NAME, &num_cpus::get().to_string())
-                .context(format!("Can't write {}", DEX2OAT_THREADS_PROP_NAME)),
-        )?;
         let output = to_binder_result(
             compile_cmd(&self.dex2oat_path, args, authfs_service, fd_annotation)
                 .context("Compilation failed"),