[M120 Migration][Audio] Fix wav audio playback issue
1. fixup for https://review.tizen.org/gerrit/#/c/285499/
remove hard code, or it will fills wrong sample format after converting
`VCodecContext` to `AudioDecoderConfig` for audio.
2. use default renderer for wav audio
since most wav files contain PCM audio, it should not use Tizen
multi-media pipeline for this type of raw audio playback.
for more information, see
DF230908-00250.
refer to:
https://review.tizen.org/gerrit/#/c/298608/
Change-Id: I176d885ced3a120e3f8279bf0299d78cc1874f75
Signed-off-by: peng.yin <peng8.yin@samsung.com>