L2CAP: Fix dynamic channel refcount and ERTM timeout

Added a simple PTS Transmit I-frames and S-Frame Transmissions
Exceed MaxTransmit to verify ERTM DataController could correctly close
the channel on error.

Test: run_cert.sh
Bug: 145006212
Bug: 141557006
Change-Id: Ic6e58cb7022b0df1b7d7eaefff2168b0044b6ec3