Rename key declaration to start with "KEY"

CarrierConfigTeset validates carrier_config xmls by comparing them to
static fields starting with "KEY_" declared in CarrierConfigManager.
This commit renmaes the key so the test passes.

Change-Id: Iebb11739ae16e56fe1a0b2fdc9a3e005a71858dc
Test: runtest carrierconfig-unit
1 file changed