codec2: add smoothfactor when checking n-th work

pipeline watcher's queued work counter included smoothfactor, if we
don't add it in elapsed(), it is easy to cause CCodec queue call timeout

CRs-Fixed: 2984012
Test: Verified on OnePlus 9 that YouTube video does
      not unpause itself.
Change-Id: Ia2dbf3a7cf0da4805398cf44780ad3dacbaf1a1b

media/codec2/sfplugin/CCodecBufferChannel.cpp

@@ -2720,7 +2720,7 @@ PipelineWatcher::Clock::duration CCodecBufferChannel::elapsed() {
     size_t outputDelay = mOutput.lock()->outputDelay;
     {
         Mutexed<Input>::Locked input(mInput);
-        n = input->inputDelay + input->pipelineDelay + outputDelay;
+        n = input->inputDelay + input->pipelineDelay + outputDelay + kSmoothnessFactor;
     }
     return mPipelineWatcher.lock()->elapsed(PipelineWatcher::Clock::now(), n);
 }