Wi-Fi: Ping the driver for wifi-only devices

Wifi-only devices are not capable to find APs with hidden SSID unless a DRIVER COUNTRY command
will send to wifi driver. This change has:

- Send DRIVER COUNTRY command to ping the driver (to correct the seek of hiddens SSIDs)
- Save mCountryCode as uppercase because the wifi_countrycode_values array is in uppercase.
  Otherwise the preference will not be found.

Patchset 7: Rebase
            Do not set mCountryCode if country is null

Change-Id: Ie0f838aef07eaf683b713f7f0e46ff3c751523ab

Conflicts:
	wifi/java/android/net/wifi/WifiNative.java
	wifi/java/android/net/wifi/WifiStateMachine.java
Allow setting a per-device default configuration for STATUS_BAR_BATTERY

Batteryless devices (like TV-connected mediacenters/STBs) don't need
the battery icon there at all.

Change-Id: Iac7e1b0b813c260bc78f4733409a30da7bda248d

Conflicts:
	packages/SettingsProvider/res/values/defaults.xml
telephony: set additional audioparameters for incall audio (1/2)

Change-Id: Icbf02a80f170559ad4a5d160ed254cbe81704df6

Conflicts:
	core/res/res/values/symbols.xml