indexlibv2版本的单测OfflineBuilderV2Test(OfflineBuilderV2Test.testNormalTableParallelBuild)，运行时异常

1. aios/apps/facility/build_service/build_service/builder/test/OfflineBuilderV2Test.cpp，270行，这里应该生成indexlibv2::document::DocumentPtr吧？否则会在比如aios/storage/indexlib/document/extractor/plain/PrimaryKeyInfoExtractor.cpp的PrimaryKeyInfoExtractor::IsValidDocument函数中，dynamic_cast(doc)返回空，导致不通过，返回false，也就是一条都没有加进去

2. 尝试用旧的normal_document的ConstructNormalDocumentV2方法，生成v2的normal document并转化数据结构继续测，但发现，v2的docBatch在AddDcoument时，会core掉，正在编dbg版本看原因

分支：main
dev/1.1.0也会有问题，其他分支无这个单测文件

Start with aios/apps/facility/build_service/build_service/builder/test/OfflineBuilderV2Test.cpp around line 270 and the OfflineBuilderV2Test.testNormalTableParallelBuild case. Then trace PrimaryKeyInfoExtractor::IsValidDocument in aios/storage/indexlib/document/extractor/plain/PrimaryKeyInfoExtractor.cpp and investigate the v2 docBatch AddDocument crash using a debug build. Done means the test runs without the dynamic_cast failure, documents are added, and no core occurs.

Written by the indexing model from the issue text.