* Revert "Removing redundant constant. (#4588)"
This reverts commit be0493b.
* Revert "Spanner: Changed _rows to list (#4583)"
This reverts commit 0e4fc30.
* Revert "Do not use easily-misread glyphs in Firestore auto-IDs. (#4107)"
This reverts commit 8715da91470904deeed368ac7064dee32c639779.
Reverts #4107