Revert "stagefright: allow for minUndequeuedBufs to be one less"

This reverts commit 1faa41704e0b976e546321effcb09a85767d51ba.
Revert "mediaplayer: keep more buffers with the BufferQueue"

This reverts commit b635b0e66b257ab442e230bca96afd5105cf6829.