[2/2] OmniGears: Change of default stream type controlled by volume rocker

PS10: handling of different values to use as default within settings

NOTE: tablets need an overlay at the device tree of custom_arrays.xml
without ringer value included (doesn't break anything if not present though)

Base: https://gerrit.omnirom.org/#/c/2340
Change-Id: I9e2113a6366ab767ad3f41215f6e083fef7dd35f