Don't clear NR state when screen off

Keep the last known PCC values between screen off/on.
We may miss some indications in between, but better UX to maintain the icon across screen on/off and wait for the next indication.
Regression from ag/24136943

Test: atest NetworkTypeControllerTest
Bug: 309848456
Change-Id: I783f94afd68912f28e0cc16912ee0b078cb2c299
Merged-In: I783f94afd68912f28e0cc16912ee0b078cb2c299
(cherry picked from commit 53125661)