Decoder: Fixed error handling for dangling fields

In case of dangling fields with gaps in frames enabled,
field pic in cur_slice was wrongly set to 0.

This would cause dangling field to be concealed as a frame, which would
result in a number of MB mismatch and hence a hang.

Bug: 34097672
Change-Id: Ia9b7f72c4676188c45790b2dfbb4fe2c2d2c01f8
(cherry picked from commit 1a13168ca3510ba91274d10fdee46b3642cc9554)
diff --git a/decoder/ih264d_utils.c b/decoder/ih264d_utils.c
index bc5c484..8d02d0e 100644
--- a/decoder/ih264d_utils.c
+++ b/decoder/ih264d_utils.c
@@ -1557,7 +1557,6 @@
     ps_cur_slice = ps_dec->ps_cur_slice;
     ps_pic_params = ps_dec->ps_cur_pps;
-    ps_cur_slice->u1_field_pic_flag = 0;
     i4_frame_gaps = 0;
     ps_dpb_mgr = ps_dec->ps_dpb_mgr;