Add TapPacketReader#startAsyncForTest, poll am: 046d253d63 am: 97825354b8 am: 82094abeb0 am: b51ecd456c

Original change: https://android-review.googlesource.com/c/platform/frameworks/libs/net/+/1435132

Change-Id: I649db90a42e6859ef45632a32559d604c16058dc
tree: 260c2497fc1bb2714923a9d6dd92f6f6f0e301c5
  1. staticlibs/