[TO M50] Enable implicit signalling for HE AAC v1 & v2 in ADTS.

This allows MSE to playback HE AAC v1 (Spectral Band Replication) and
v2 (Parametric Stereo) in the ADTS (.acc) container. ADTS is not
capable of explicitly signaling these profiles, so the frame's
metadata will claim the stream is an earlier profile (e.g AAC LC) and
the decoder will later tell us its actually HE AAC. See

For more background, see these sections of 2009 ISO-14496-3
1.6.5.2 Implicit and explicit signaling of SBR
1.6.6.2 Implicit and Explicit Signaling of Parametric Stereo

TEST=new media unit tests and all manual tests in bug report
BUG=534301, 177872

Review URL: https://codereview.chromium.org/1805013003

Cr-Commit-Position: refs/heads/master@{#383478}
(cherry picked from commit 8a400694209ce5d56e013673f8c9e8a2b0a1017c)

TBR=dalecurtis@chromium.org, ccameron@chromium.org

Review URL: https://codereview.chromium.org/1838203003 .

Cr-Commit-Position: refs/branch-heads/2661@{#424}
Cr-Branched-From: ef6f6ae5e4c96622286b563658d5cd62a6cf1197-refs/heads/master@{#378081}
12 files changed