Remove unused code system/stack/l2cap/l2c_link am: 5e73dfe7 am: bee2bc15...

Remove unused code system/stack/l2cap/l2c_link am: 5e73dfe7 am: bee2bc15 am: d8c928c1 am: c78c448c am: ca3ff8c0

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Bluetooth/+/2084123



Change-Id: Ia2ae5322246c0553aafc084e0cc9f900f0e5ca5c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>