Decoder: Fixed allocation of pv_map_ref_idx_to_poc_buf.

Increased allocation to include reference list1 also by
default. In the case of error, we could get B_SLICES
even in BASE_PROFILE. The initialization in the
dec_slice_struct_t slice structure has also been
modified accordingly.

Test: run poc with and without this patch
Bug: 38496660
Change-Id: I3451d79bbcd9f0d7a80981a9897f877b7f0812bd
(cherry picked from commit a925a6b539642c8749c91a6f33e362eda8c4a5b6)