[aaudio/echo] Audio streams should be kept running to avoid startup latency about android-audio-high-performance

[dturner]

This will require an extra button to start/stop the input and output streams for the selected audio devices. Typical processes:

#1 start streams
audio devices selected
"start streams" button pressed
input stream created and started
output stream created and started
flush input stream
0s (silence) written to output stream

#2 start echo
"start echo" button pressed
input stream read and written to output stream

#3 stop echo
"stop echo" button pressed
0s (silence) written to output stream

#4 stop streams
"stop streams" button pressed
input and output streams stopped and destroyed

[codingjeremy]

This sample has been deprecated/archived (check README for more information on newer samples related to this technology).

As recommended by GitHub, we are closing all issues and pull requests.