Create firmware and persist in GSI for arm_ab

Some SoC vendors require firmware and persist directores to mount.
This must be provided in GSI for arm_ab not only for arm64_ab.
Once the directories are moved to /vendor, these policies for root
must be removed.

Bug: 36764215
Bug: 73720182
Test: GSI boot with 32bit devices
Change-Id: Ic5c6bb615c39853d51d233c00d2d9e8ee2c57802