Update test-resample to handle multichannel

Option -c # specifies number of channels (mono default).
Option -s to specify stereo is removed (-c 2 replaces).
Option -h to specify WAV header is removed (WAV is now default).

Change-Id: Iba4b83806028a8a9c1ddba6f555182d214ef73ff
Signed-off-by: Andy Hung <hunga@google.com>