Update Provisioning API name and doc per API review

Bug: 178456092
Test: atest TeleServiceTests:com.android.phone.RcsProvisioningMonitorTest
Test: atest CtsTelephonyTestCases:android.telephony.ims.cts.ImsServiceTest
Change-Id: I2a5c6c9a760479361ce66401f87316dd3c9d909d