Switch compsvc to use authfs_service

With authfs_service, we no longer need compsvc_worker.rs and authfs.rs
for the task setup. Now, for each request, compsvc can just request
FDs from authfs_service then pass to the task.

Also, fixed the integer type of remote FD to match ParcelFileDescriptor.

Bug: 194717985
Test: atest ComposHostTestCases
Change-Id: I8c0be106243778ac20e7cd96a778db4e34aef051
diff --git a/authfs/aidl/Android.bp b/authfs/aidl/Android.bp
index 35a3c4a..9504037 100644
--- a/authfs/aidl/Android.bp
+++ b/authfs/aidl/Android.bp
@@ -9,7 +9,10 @@
     backend: {
         rust: {
             enabled: true,
-            apex_available: ["com.android.virt"],
+            apex_available: [
+                "com.android.compos",
+                "com.android.virt",
+            ],
         },
     },
 }