ImsProvisioningController returns provisioned when provisoning has not completed

Delete code that access deprecated carrier config key, and hand over to
ImsProvisioningController

Bug: 230794289
Test: atest ImsManagerTest, ImsServiceTest
Test: manual with TMO, ATT SIM
1. add carrier config carrier_volte_provisioning_required_bool as true
2. device reboot
3. check IMS registration and imsprovisioningstatus_X.xml file is created by ImsProvisioningLoader
Change-Id: I289e0787ab90957a5c5eb03b4bff9b0ee35160d6