Do not read the block device when generating the care map

This remove the fstab dependency when building the OTA package for
marlin/sailfish.

Bug: 35811655
Test: OTA package builds successfully for sailfish.
Change-Id: If223d11dddca396c47262042c576f9e7d0cb5b33
(cherry picked from commit 7d051adc3be56594ee755bf4ed06b6597fd62268)
1 file changed