Create instance.img

The file is a per-VM persistent storage which will contain identity
information like the certs of the payload.

As the first step, this change creates instance.img upon creation of a
VM and passes it to virtualizationservice. For now, the file is not
passed down to crosvm yet.

Bug: 193504400
Test: atest MicrodroidHostTestCases
Change-Id: I44115a93abdd23c36a4c52a38e5355bfa3bf69b3
diff --git a/virtualizationservice/src/aidl.rs b/virtualizationservice/src/aidl.rs
index 3ebde6f..44d89e7 100644
--- a/virtualizationservice/src/aidl.rs
+++ b/virtualizationservice/src/aidl.rs
@@ -339,6 +339,8 @@
 ) -> Result<VirtualMachineRawConfig> {
     let apk_file = config.apk.as_ref().unwrap().as_ref();
     let idsig_file = config.idsig.as_ref().unwrap().as_ref();
+    // TODO(b/193504400) pass this to crosvm
+    let _instance_file = config.instanceImage.as_ref().unwrap().as_ref();
     let config_path = &config.configPath;
 
     let mut apk_zip = ZipArchive::new(apk_file)?;