btshell: Set connectable/scannable to 1 when legacy is used
btshell: Set connectable/scannable to 1 when legacy is used

For the case when legacy adv is used in most of cases connectable and
scannable shall be set, therefore make it default.

Those values can be overwritten

apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble