Fix for bug206007, power dialog change "Why?" to "Battery use"

    <!-- When the battery is low, this is the label of the button to go to the

         power usage activity to find out what drained the battery. -->

    <string name="battery_low_why">Why?</string>

    <string name="battery_low_why">Battery use</string>

    <!-- Title of the alert when something went wrong in the factory test. -->

    <string name="factorytest_failed">Factory test failed</string>