Add CTS for creating keepalive offloads on cellular

Bug: 134352656
Test: atest android.net.cts.ConnectivityManagerTest (--instant)
Change-Id: Ia7b1111abe687efad032a8c9205990c97a769fcd
1 file changed
tree: c068d3be34bab954f3b0da6344c22d36dfbde106
  1. tests/