[automerger skipped] Move TapPacketReader into its own utility class. am: 3e814f7938 -s ours am: 03c384e0a8 -s ours am: 75838e9223 -s ours am: b811f582b2 -s ours

am skip reason: Change-Id I73e9c1919956aa665a8cccec11d3444e486426ec with SHA-1 3e814f7938 is in history

Change-Id: Ifd397e1035da20458d0fb95bfc8a673161b4ea04