lshal: Allow read to timeout in debug()

Start timing when debug() has returned. When the specific
timeout has reached (currently 1s) and the relay thread
has not finish, tell the relay thread to stop.

Test: while true; do date; lshal debug android.hardware.health.storage@1.0::IStorage/default; done
Test: lshal_test

Bug: 111997867
Change-Id: Ib9235d3bd2fc3a54eb316da8d8b59d987988b134