SMS service loads MMS config directly instead

getCarrierConfigValues() is removed from MmsManager and SMS service
loads Carrier configuration values directly since MmsService could
return null or cached config instead if an app requests the config by
receiving ACTION_CARRIER_CONFIG_CHANGED before the config is loaded
newly in MmsService by ACTION_CARRIER_CONFIG_CHANGED.

Bug: 145768042
Test: manual

Change-Id: Idc21015cab2902bd0f67e2131ea89b04c4fc4f5e
Signed-off-by: Taesu Lee <taesu82.lee@samsung.com>