Decoder: Detect change of mbaff flag in SPS

Change in Mbaff flag needs re-initialization of NMB group
and other variables in decoder context.

Bug: 64380237
Test: ran poc on ASAN before/after
Change-Id: I0fc65e4dfc3cc2c15528ec52da1782ecec61feab
(cherry picked from commit d524ba03101c0c662c9d365d7357536b42a0265e)
