Http streaming cannot play video whose duration is less than 5s

onPollBuffering() monitors EOS(finalStatus == ERROR_END_OF_STREAM),
then notifyPreparedAndCleanup(finalStatus) notifies prepared error.

Previous Google's patch "GenericSource: fix error handling during
preparing or rebuffering" should focus on error except ERROR_END_OF_STREAM.

Bug: 134911527
Test: http streaming can play a mp4 video whose duration is less than 5s
Change-Id: I5c738bbe7242314b24463679b5bd996ab59d2b04
(cherry picked from commit 89703072ec4edf7a384ec07024debc0a6e085ae0)