Update rocksdb to 7.0.2
Update rocksdb to 7.0.2

Summary: Required by the OSS build of Glean.

Reviewed By: zsol

Differential Revision: D35182459

fbshipit-source-id: 657bb341397947605cb0524db17e99813757fb48

facebook/folly,facebook/folly,facebook/folly,facebook/folly,facebook/folly