exynos_camera: update sports scene name

The 'sports' scene mode has been renamed to 'action' scene mode
to match the 4.4 camera configuration

Change-Id: I1efcd57f137ee0d73f22ab20031832c7f283381c
Bring back the SECONDARY_STORAGE variable

This variable is a requirement in KK as newly introduced APIs
such as Context.getExternalFilesDirs uses it to retrieve
secondary storage locations on the device.

Change-Id: I17708c93498da5979c5742cad32232a34490bf5f