[avb] Keep Digest reference in avb hash descriptor to avoid copy

Test: atest libpvmfw_avb.integration_test
Bug: 279557218
Change-Id: I82fe78c4389d1b58a6a7ebcd50f1988c91c33d10
diff --git a/pvmfw/avb/src/verify.rs b/pvmfw/avb/src/verify.rs
index 05a6492..ded0766 100644
--- a/pvmfw/avb/src/verify.rs
+++ b/pvmfw/avb/src/verify.rs
@@ -119,7 +119,7 @@
         verify_vbmeta_has_only_one_hash_descriptor(&descriptors)?;
         return Ok(VerifiedBootData {
             debug_level: DebugLevel::None,
-            kernel_digest: kernel_descriptor.digest,
+            kernel_digest: *kernel_descriptor.digest,
             initrd_digest: None,
             public_key: trusted_public_key,
         });
@@ -143,8 +143,8 @@
     let initrd_descriptor = descriptors.find_hash_descriptor(initrd_partition_name)?;
     Ok(VerifiedBootData {
         debug_level,
-        kernel_digest: kernel_descriptor.digest,
-        initrd_digest: Some(initrd_descriptor.digest),
+        kernel_digest: *kernel_descriptor.digest,
+        initrd_digest: Some(*initrd_descriptor.digest),
         public_key: trusted_public_key,
     })
 }