m7-common: overlay vzw-specific eri.xml

The mcc/mnc specific config.xml in values-xxx and xml-xxx were
apparently copied from Sprint. I see no reason they sould have been
included in the first place. This is re-affirmed by decompiling the
frameworks apks from stock.

Include more mcc/mnc eri overlays to correct the R(oaming) symbol in 3G.

Change-Id: I2b279cb03c28b7c2a580440a7456dee113338d3c