Summary:
The patch adds support for injecting errors when reading from `RandomAccessFile`
using `FaultInjectionTestEnv`. (This functionality was curiously missing
w/r/t `RandomAccessFile`, even though it was implemented for `RandomRWFile`.)
The patch also fixes up a test case in `blob_db_test` which uses `FaultInjectionTestEnv`
but has so far relied on reads from `RandomAccessFile`s succeeding even after
deactivating the filesystem.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7447
Test Plan: `make check`
Reviewed By: zhichao-cao
Differential Revision: D23971740
Pulled By: ltamasi
fbshipit-source-id: 8492736cb64b1ee138c658822535f3ff4fe560c6