Hook CarrierConfigLoader<->SubscriptionInfoUpdater

Add a hook so that when CarrierConfigs are loaded,
the data is first passed to SubscriptionInfoUpdater
to possibly update fields in the SubscriptionInfo
before the CARRIER_CONFIG_CHANGE broadcast is sent
to inform apps that the new subscription is ready
for use.

Bug: 123721160
Test: atest SubscriptionInfoUpdater
Change-Id: I864ae3355ea9689a43743e2d6fc7f8b55fef6524