Increase customization options for wfcSpnFormats

Expand wfcSpnFormats with more options, in order to support
requirements from more operators.

Five new options are added in this patch. The list of available options
becomes:
0: %s
1: %s Wi-Fi Calling
2: WLAN Call (New)
3: %s WLAN Call (New)
4: %s Wi-Fi (New)
5: WiFi Calling | %s (New)
6: %s VoWifi (New)

strings.xml in values-mcc302-mnc370 and values-mcc302-mnc720 was deleted.
The same requirement can now be achieved by configuring KEY_WFC_SPN_FORMAT_IDX_INT
or KEY_WFC_DATA_SPN_FORMAT_IDX_INT to 4.

Bug: 114303633
Test: Manual
Change-Id: I5daf6b49c838df823aed4b84f5f80c68f46b2970