NrConnectedState can't start NR Icon timer

Because the NrConnectedState receives the
EVENT_DATA_ACTIVITY_CHANGED before the EVENT_NR_FREQUENCY_CHANGED,
and it causes the state's name is changed to STATE_CONNECTED
from STATE_CONNECTED_MMWAVE. Therefore, NrConnectedState can't start
the timer while it receives the EVENT_NR_FREQUENCY_CHANGED.

Bug: 157388635
Test: atest NetworkTypeControllerTest (PASS)
Change-Id: Id2fe11c51684f3fa76f5a84cc92bf0b91565fb99