Seq header shouldn't change in the middle of frame

A different sequence header OBU should not be received between a
frame header OBU and the last tile group OBU of that frame.

This cherry-picks the upstream libaom commit
7ad847ac64e93f766d045f0058b0469d168b3e85:
https://aomedia.googlesource.com/aom/+/7ad847ac64e93f766d045f0058b0469d168b3e85

Test: test_libaom --gtest_filter=*InvalidFileTest*
Bug: b/142530197

Merged-In: Ibdc62e7092685357b0246b68f523e5296d13e5bd
Change-Id: Ibdc62e7092685357b0246b68f523e5296d13e5bd
5 files changed