fs_mgr: remount: add -T fstab argument

Allow selection of an fstab file.  This is to mirror the built-in
functionality associated with init mount_all <fstab> command.

Test: adb-remount-test.sh
Bug: 122602260
Change-Id: I5fc2f3707c1dafd687c826eaccbaab03a408035b
1 file changed