init.rc: move load_system_props to beginning of 'on fs'

ro.logd.kernel, ro.config.low_ram, ro.logd.timestamp and ro.debuggable
need to be retrieved prior to logd start in order for the service to
behave in a configured manner.  Other essential services are also
dependent on these system properties as well, so it just makes sense
to pick them all up first in 'on fs'.

Test: smoke test
Bug: 37425809
Change-Id: I33ad185f397ee527ed3c84cc2bcb40ff8ca785b5