Telephony: fix getIccOperatorNumeric

The current logic is broken because getDataNetworkTypeForSubscriber
returns the translated network type while getFamilyFromRadioTechnology
requires the raw radio technology.

Fixed by using Phone.getIccCard API instead.

Fixes broken APN settings when connected to HSDPA.

Change-Id: I836f6d4316984cdc8f5a34203c83ebf33a41b121