CCodecBufferChannel: remove assumption that pipeline clears quickly on input EOS

Bug: 223315440
Test: presubmit
Change-Id: I78dbf8062ddfec8861733c25cf85e2369c1cbf19
(cherry picked from commit 05b5120253a087a84f158a7e55737698269e8ae8)
Merged-In: I78dbf8062ddfec8861733c25cf85e2369c1cbf19
1 file changed