kvm: align MultipathNVMeOFPool with KVMStoragePool API change

Reported by @slavkap: building this branch against current main produces a compile error in MultipathNVMeOFPool because the KVMStoragePool interface drifted between when this PR was last rebased (2026-05-22) and main today (2026-06-09):

- checkingHeartBeat(HAStoragePool, HostTO) was renamed to hasHeartBeat(HAStoragePool, HostTO)

- vmActivityCheck(...) was renamed to hasVmActivity(...) with the same signature

Update the two overrides accordingly (both still return null as before — MultipathNVMeOFPool does not participate in the KVM-side HA heartbeat). Mirrors how MultipathSCSIPool implements them.

Verified compile via mvn -pl plugins/hypervisors/kvm -am -DskipTests compile.

Signed-off-by: Eugenio Grosso <eugenio.grosso@gmail.com>

Author: Eugenio Grosso

plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/MultipathNVMeOFPool.java

@@ -147,10 +147,10 @@ public String createHeartBeatCommand(HAStoragePool primaryStoragePool, String ho
     @Override public String getStorageNodeId() { return null; }
 
     @Override
-    public Boolean checkingHeartBeat(HAStoragePool pool, HostTO host) { return null; }
+    public Boolean hasHeartBeat(HAStoragePool pool, HostTO host) { return null; }
 
     @Override
-    public Boolean vmActivityCheck(HAStoragePool pool, HostTO host, Duration activityScriptTimeout,
+    public Boolean hasVmActivity(HAStoragePool pool, HostTO host, Duration activityScriptTimeout,
             String volumeUUIDListString, String vmActivityCheckPath, long duration) {
         return null;
     }