Add instance creation to composd.

At startup we validate the files needed for the current instance exist
and are valid; if anything goes wrong we re-create them.

Bug: 186126194
Test: Manual, via composd_cmd.
Change-Id: Iaf19a74df14a91436c4cb4435f0286fa09307db8
diff --git a/compos/composd/Android.bp b/compos/composd/Android.bp
index 5c968b8..30d07ab 100644
--- a/compos/composd/Android.bp
+++ b/compos/composd/Android.bp
@@ -9,6 +9,7 @@
     prefer_rlib: true,
     rustlibs: [
         "android.system.composd-rust",
+        "android.system.virtualizationservice-rust",
         "compos_aidl_interface-rust",
         "libandroid_logger",
         "libanyhow",