Guard uevent migration with genfs label version

android.hardware.usb.flags.enable_udc_sysfs_usb_state_update introduces
a new way to detect usb state update, however, it depends on system
server having access to sysfs_udc fs context, which is only guaranteed
in genfs label version later than 202404. Guard the feature enablement
with genfs label version check.

Bug: 339241080
Test: Tested on shiba
Flag: android.hardware.usb.flags.enable_udc_sysfs_usb_state_update
Change-Id: Ib7de2e780c8046a7745e650c1dc6c04eaca1b4f5