Moving LappedTransform, Blocker and AudioRingBuffer.

LappedTransform is only used in BandwidthAdaptationTest and therefore it
should not be anymore a visible target under common_audio.
This CL moves LappedTransform and other two classes it depends on (and which
are not used elsewhere) to modules/audio_coding/codecs/opus/test.

Bug: webrtc:9577, webrtc:5298
Change-Id: I1aa8052c2df2b2b150c279c0c9b1001474aed47a
Reviewed-on: https://webrtc-review.googlesource.com/96440
Commit-Queue: Alessio Bazzica <alessiob@webrtc.org>
Reviewed-by: Alex Loiko <aleloi@webrtc.org>
Reviewed-by: Henrik Lundin <henrik.lundin@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24509}
diff --git a/modules/audio_coding/BUILD.gn b/modules/audio_coding/BUILD.gn
index de2aeb7..0321c31 100644
--- a/modules/audio_coding/BUILD.gn
+++ b/modules/audio_coding/BUILD.gn
@@ -2093,6 +2093,8 @@
       "../../test:rtp_test_utils",
       "../../test:test_common",
       "../../test:test_support",
+      "codecs/opus/test",
+      "codecs/opus/test:test_unittest",
       "//testing/gtest",
       "//third_party/abseil-cpp/absl/memory",
     ]