Use unstable networkstack AIDLs in development branches

Development branches should use the -unstable version of the
NetworkStack AIDLs so that refreezing is not necessary for each
modification.
The versions will be re-frozen before each release instead.

Bug: 157534516
Change-Id: I74b4a16266bda7b8ac740b3a0193268da260fc2f
Test: m
1 file changed
tree: 2a05ccb897a9357a6300165bbe0703411f46c3e6
  1. Tethering/