Update the format of RCS provisioning config XML

Bug: 184275686
Test: atest FrameworksTelephonyTests:com.telephony.ims.RcsConfigTest
Test: atest TeleServiceTests:com.android.phone.RcsProvisioningMonitorTest
Test: atest CtsTelephonyTestCases:android.telephony.ims.cts.ImsServiceTest
Merged-In: I16642ad3ddbd6561e32135269f488578c5bb436b
Change-Id: I16642ad3ddbd6561e32135269f488578c5bb436b