[FEATURE] Speed up the registering on reassign

### Code of Conduct

- [x] I agree to follow this project's [Code of Conduct](https://www.apache.org/foundation/policies/conduct)

### Search before asking

- [x] I have searched in the [issues](https://github.com/apache/incubator-uniffle/issues?q=is%3Aissue) and found no similar issues.

### Describe the feature

The reassign rpc costs too much time when registering.

### Motivation

_No response_

### Describe the solution

_No response_

### Additional context

_No response_

### Are you willing to submit PR?

- [ ] Yes I am willing to submit a PR!

The issue names the reassign RPC during registration but gives no file, test, baseline, target, or proposed solution. Start by tracing the registration and reassign path in the Java code and establish a reproducible timing comparison. The definition of done is not specified, so maintainer clarification is needed before implementation.

Written by the indexing model from the issue text.