Subject: Propose fix for 1.10 release: Prevent NPE in getLocalSize()


I’d like to propose including https://github.com/apache/geode/pull/3913/commits/6f1814d1f719cc06b13769c40a9d6d01f99f927c <https://github.com/apache/geode/pull/3913/commits/6f1814d1f719cc06b13769c40a9d6d01f99f927c> in the Geode 1.10 release.

This commit fixes an issue where a NullPointerException is thrown from PartitionedRegion.getLocalSize() when the statistics callback sampler is invoked before a PartitionedRegion is initialized.

- Aaron