Introduce a new config item: config_lte_capable

config_lte_capable is set to true when the device is
LTE capable.

CRs-Fixed: 628506

Conflicts:
core/res/res/values/config.xml
core/res/res/values/symbols.xml
Change-Id: I0032ff41a37509eb0acf25f1ee08de6cbd01511e