WifiController: fix high perf lock sometimes not respected

When the device screen is turned off, the state is DeviceActive for
15 minutes. In this time, high perf lock is not respected and
Wi-Fi power-saving mode will be turned on because screen is off.

Fix by adding a new DeviceActiveHighPerfState.

Change-Id: I71074beec4d41286dea0861107d7931da205aca2
JIRA: CYAN-2860