Support system_dlkm in GSI

From Android 13, all devices must include a system_dlkm partition.
The patch enables system_dlkm on all GSI targets to support the devices
with system_dlkm partition, and be compatible with old devices
without a system_dlkm partition.

With patch, there is no /system/system_dlkm, and add a symlink
/system/lib/modules -> /system_dlkm/lib/modules

Bug: 256984997
Test: make gsi_arm64-user and aosp_arm64-user; check system folder
Change-Id: I2453ec43d584423cc4d5f0e23405f0ae9b6c5c90