Enable binder txn tracing more broadly

Previously, binder txns were only traced for txns from sysui/launcher
to system_server.

aosp/I57857443495475b1d2efa82cbcb448af5d37a79a and
aosp/I01d520afa8e26eabb97318192151b707b002c28b enabled aidl tracing
if aidl#gen_trace or aidl#generate_traces respectively is true.

Guarded tracing on the availability of txn names instead

Test: Manual
Bug: 161393989
Change-Id: Iffc4bb534d239c07d2e4d43ab43a9ed76abe7496