Factor out Rust client library for VirtualizationService.

This reduces code duplication, and will also be useful for Rust tests.

Test: ComposHostTestCases compos_key_tests
Change-Id: I13c41d3b2bbe506495b723e7739f3181cb033f0f
diff --git a/vm/Android.bp b/vm/Android.bp
index d1d53d0..2b83ca7 100644
--- a/vm/Android.bp
+++ b/vm/Android.bp
@@ -20,6 +20,7 @@
         "libserde",
         "libstructopt",
         "libvmconfig",
+        "libvmclient",
         "libzip",
     ],
     apex_available: [