Remove hidden APIs usage regarding to dump

Classes inside the incoming connectivity module will not be able
to access hidden APIs. The hidden DUMP_FLAG_PRIORITY_* flags
usage should be replaced. It was used to control the dump
priority. DEFAULT priority for services which is treated the
same as NORMAL priority. ConnectivityServiceInitializer took
both NORMAL and HIGH. It trigger different information dumped.
It's replaced with dumpsys that does not send "--dump-priority"
arguments to the service. Thus, design is replaced with
local parsing inside ConnectivitySerivce to provide equivalent
dump.

Bug: 172183305
Test: m ; flash and boot up
Test: adb bugreport ; adb dumpsys connectivity
Change-Id: Ib3c9d8692eb4382cd106734a1a716df6f48ffca4