base: apply custom timeout upon volume dialog instantiation

The custom timeout is correctly applied at runtime, but after a reboot
the VolumePanel will revert to the default timeout, since the custom
value is not read from the config during instantiation

Change-Id: Ifa389011247adeee70ad5f3ff0b0072dd3dff02a
Merge "base: apply custom timeout upon volume dialog instantiation" into android-4.4