Warning: A lot of buffers are being dropped

Android native apps are being developed.

target device tcc893x dual core 1G, ram 1G

setting in
width = width>0?width:640;
height = height>0?height:480;
framerate = framerate>0?framerate:20.0;

case : audio off , video on
SimpleStreamSet simpleStreamSet = SimpleStreamSet.defaultConfig(false, true);

it's works good

but audio on, video on
SimpleStreamSet simpleStreamSet = SimpleStreamSet.defaultConfig(true, true);

very slowly...

07-25 14:28:14.786 2963-2976/com.matescorp.matebot E/g_printerr﹕ ==== Warning message start ====
07-25 14:28:14.786 2963-2976/com.matescorp.matebot E/g_printerr﹕ Warning in element sink.
07-25 14:28:14.786 2963-2976/com.matescorp.matebot E/g_printerr﹕ Warning: A lot of buffers are being dropped.
07-25 14:28:14.786 2963-2976/com.matescorp.matebot E/g_printerr﹕ Debugging info: gstbasesink.c(2846): gst_base_sink_is_too_late (): /GstPipeline:media-renderer-2/GstBin:video-renderer-bin-0/GstGLImageSinkBin:video-renderer-sink/GstGLImageSink:sink:
There may be a timestamping problem, or this computer is too slow.
07-25 14:28:14.786 2963-2976/com.matescorp.matebot E/g_printerr﹕ ==== Warning message stop ====

Reproduce the Android case using SimpleStreamSet.defaultConfig(false, true) and then SimpleStreamSet.defaultConfig(true, true), comparing the GstGLImageSink warnings and playback speed. Start with the media pipeline around GstGLImageSink and the reported timestamping path. Done means the audio-and-video configuration no longer becomes very slow or drops large numbers of buffers.

Written by the indexing model from the issue text.