IMEI Hardening: Fix key attestation leaf certificate generation

Bug: 429744600
Flag: EXEMPT bugfix
Change-Id: I1b8c878ccee42b120ce07fe1daf3e20b94d8ed6a
diff --git a/DeviceLockController/src/com/android/devicelockcontroller/util/KeyAttestationUtil.java b/DeviceLockController/src/com/android/devicelockcontroller/util/KeyAttestationUtil.java
index 72697ed..0a7c8e1 100644
--- a/DeviceLockController/src/com/android/devicelockcontroller/util/KeyAttestationUtil.java
+++ b/DeviceLockController/src/com/android/devicelockcontroller/util/KeyAttestationUtil.java
@@ -55,6 +55,7 @@
                         .setDigests(KeyProperties.DIGEST_SHA256,
                                 KeyProperties.DIGEST_SHA384,
                                 KeyProperties.DIGEST_SHA512)
+                        .setAttestationChallenge(new byte[0])
                         .build());
         // Generate the key pair. This will result in calls to both generate_key() and
         // attest_key() at the keymaster2 HAL.