Add TcpKeepalivePacketData to SystemApi am: 11511b31f6 am: 349ba03274

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1494038

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ic764adda49e414e6ed34a101fd83c3fc62f5734c
tree: 90790175763eb87e20bc1ddd48fad38ab9cabc1d
  1. core/
  2. services/
  3. tests/
  4. OWNERS