Summary:
- Used ChrootEnv so the database and backup Envs are isolated in the filesystem.
- Removed DifferentEnvs test since now every test uses different Envs
Depends on D57543
Test Plan:
- ran backupable_db_test
- verified backupable_db_test now catches the bug when D57159 is backed out (this bug previously passed through the test cases, which motivated this change)
Reviewers: sdong, lightmark, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D57615
e61ba052b3