Move AudioDecoderG722 next to AudioEncoderG722

Move AudioDecoderG722 next to AudioEncoderG722

All AudioDecoder subclasses have historically lived in NetEq, but they
fit better with the codec they wrap.

BUG=webrtc:4557
Committed: https://crrev.com/ada4c130ab576120380d48f29908b6cc20ec9cf5
Cr-Commit-Position: refs/heads/master@{#9966}

[kwiberg-webrtc, 2015-09-16 12:23:08]

kwiberg@webrtc.org changed reviewers:
+ henrik.lundin@webrtc.org

[kwiberg-webrtc, 2015-09-16 12:25:56]

As noted elsewhere, this CL leads to the AudioDecoder subclass not being
excluded from the build when it should be, just as is already the case with the
AudioEncoder subclass and the codec's C implementation. I'll deal with tha
problem all at once in a future CL.

[hlundin-webrtc, 2015-09-16 12:38:28]

lgtm

[kwiberg-webrtc, 2015-09-17 09:06:00]

The CQ bit was checked by kwiberg@webrtc.org

[kwiberg-webrtc, 2015-09-17 09:06:00]

The patchset sent to the CQ was uploaded after l-g-t-m from
henrik.lundin@webrtc.org
Link to the patchset: https://codereview.webrtc.org/1346993002/#ps40001 (title:
"rebase")

[commit-bot: I haz the power, 2015-09-17 09:06:14]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1346993002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1346993002/40001

[commit-bot: I haz the power, 2015-09-17 10:12:38]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-09-17 10:12:45]

Patchset 3 (id:??) landed as
https://crrev.com/ada4c130ab576120380d48f29908b6cc20ec9cf5
Cr-Commit-Position: refs/heads/master@{#9966}