[BUILD] remove generated directory before regenerated files
[BUILD] remove generated directory before regenerated files

Change-Id: I6ea099b7d2e92235e9ee2955f73364f804c7f6c2

Parrot-Developers/libARNetworkAL,Parrot-Developers/libARNetworkAL,Parrot-Developers/libARNetworkAL,Parrot-Developers/libARNetworkAL