* Proper re-allocation of seg_map buffer when resolution changes
* Remove undesired resetting of seg_map buffer

* This resolves issues raised in

   https://bugs.chromium.org/p/aomedia/issues/detail?id=1064
   https://bugs.chromium.org/p/aomedia/issues/detail?id=1091

* Disable error_resilient_flag in resize_test as this covers more cases

* Will be enabled by default in separate patch

BUG=aomedia:1064
BUG=aomedia:1091

Change-Id: Ic3f0e47922784c66d240b52d30ba082bdb46dc3b