Move default sounds to /product

The set of audio files is frequently customized, so move the default
set to /product. The frameworks scans both of these directories.

Bug: 80410283
Bug: 118826166
Test: verify sounds available in soundpicker
Change-Id: I3bfc71b46eb64b4d4614b62c65fb8821bf1c271a
Merged-In: I3bfc71b46eb64b4d4614b62c65fb8821bf1c271a