Change config path for LE Audio Capabilities file

Since there is no different setting for sub project under same prohject,
we will change the setting file from `bluetooth/project/` to
`bluetooth/` to simplify the file structure.

Bug: 238983662
Test: make sure file added in config folder can be copied into devices
Change-Id: I1b0d6a2107f5d69fd7bf650bad314e920810c156