Update TRANS opcode in ApfGenerator for discard/transmit buffer

This commit adds update for the "TRANS" opcode to make it matches the
latest design. This opcode allows the apf_interpreter to
discard/transmit the allocated buffer.

* design doc: go/apf-v6-proposal

Bug: 293811969
Test: TH
Change-Id: Id474e500b55cb90874fed661f55d4ee64104ad94
2 files changed