fs_mgr: set ext4 fsverity feature bit

It supports a new feature "fsverity" for ext4 file-system. When someone
adds a mount option "fsverity" to fstab file, fsmgr will use tune2fs to
enable fsverity feature if kernel support.

Bug: 117437571
Test: bootable for phone projects
Change-Id: Icf35715a2f71c430468daaafcde497f8cfe9a18d