[Settings] get wrong toggle when handle the WFC changed

WFC toggle's state(EXTRA_TOGGLE_STATE) is set to the newValue after each notifyChange.
However, WFC slice gets the same newValue from EXTRA_TOGGLE_STATE when users change the toggle state
before the EXTRA_TOGGLE_STATE is updated.

Need to get the "correct" new value to set the WFC

Follow the original logic(ag/3820815), 1. don't turn on WFC and only can turn off WFC  if activationApp is not null. 2. turn on/off if  no activationApp.

Bug: 261922170
Test: m RunSettingsRoboTests -j ROBOTEST_FILTER=WifiCallingSliceHelperTest
Change-Id: I823f00029c24f1901f40757ba13e7c0f90d6c0bc