[CELEBORN-1065] Prevent the local variable 'time' declared in one 'sw…

…itch' branch and used in another

### What changes were proposed in this pull request?
- Minor code improvement in `MetaHandler`
  - Local variable 'time' declared in one 'switch' branch `AppHeartbeat` and used in another branch `WorkerHeartbeat`

### Why are the changes needed?

- Incorrect code pattern.

### Does this PR introduce _any_ user-facing change?

No.

### How was this patch tested?

CI tests.

Closes apache#2012 from bowenliang123/time.

Authored-by: liangbowen <[email protected]>
Signed-off-by: zky.zhoukeyong <[email protected]>

master/src/main/java/org/apache/celeborn/service/deploy/master/clustermeta/ha/MetaHandler.java

@@ -173,7 +173,6 @@ public ResourceResponse handleWriteRequest(ResourceProtos.ResourceRequest reques
               replicatePort,
               diskInfos,
               userResourceConsumption);
-          time = request.getWorkerHeartbeatRequest().getTime();
           metaSystem.updateWorkerHeartbeatMeta(
               host,
               rpcPort,
@@ -183,7 +182,7 @@ public ResourceResponse handleWriteRequest(ResourceProtos.ResourceRequest reques
               diskInfos,
               userResourceConsumption,
               estimatedAppDiskUsage,
-              time,
+              request.getWorkerHeartbeatRequest().getTime(),
               highWorkload);
           break;