Merge "Make some fstab functions available outside of fs_mgr" into main am: 6e1b4c5a1e am: aeeadf43ad

Original change: https://android-review.googlesource.com/c/platform/system/core/+/3200691

Change-Id: I90c782f50ca30900af99bd1d1588ae38a2b96fa9
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>