[client-vm] Build client VM CSR and sign the CSR with two keys

This cl builds the CSR that a client VM sends to the RKP VM for
remote attestation and adjusted the API accordingly as discussed
in the doc go/pvm-remote-attestation

The CSR payload is signed with both the CDI_Leaf_Priv of the
client VM's DICE chain and the attestation key. RKP VM should
verify the signature later with the CDI_Leaf_Pub extracted
from the same DICE chain in the CSR and the attestation public
key.

The new unit tests are added to config at cl/577763874.

Bug: 303807447
Test: run ServiceVmClientTestApp
Test: atest libservice_vm_comm.test
Test: atest microdroid_manager_test
Change-Id: Ic2c09e7339d9981edda028e2694fa551c911a274
diff --git a/microdroid_manager/aidl/Android.bp b/microdroid_manager/aidl/Android.bp
index 0aa8662..353e9cc 100644
--- a/microdroid_manager/aidl/Android.bp
+++ b/microdroid_manager/aidl/Android.bp
@@ -5,8 +5,12 @@
 aidl_interface {
     name: "android.system.virtualization.payload",
     srcs: ["android/system/virtualization/payload/*.aidl"],
+    imports: ["android.system.virtualizationcommon"],
     unstable: true,
     backend: {
+        java: {
+            enabled: false,
+        },
         rust: {
             enabled: true,
             apex_available: [