Use stack/l2cap/l2c_csm::channel_state_text() am: 0b9082eb am: 1bf41d3f...

Use stack/l2cap/l2c_csm::channel_state_text() am: 0b9082eb am: 1bf41d3f am: 6a27b94d am: 9892c4c2

Original change: https://android-review.googlesource.com/c/platform/system/bt/+/1496548

Change-Id: I4e762b997569d354f6746755f196250cab5fffa6