rtc: Fix to skip_encoding_non_reference_slide_change

For scene changes that occur on non_reference
frames (highest temporal layer) the encoder will do
a skip encoding. The logic to do this is in the
variance_partitioning, but this path may be bypassed
under high motion flag and sb source sad, which is not
correct. This can lead to some superblocks not being skip
encoded while others are.

This fixes the artifact observed in comment#18 of the
issue below.

Bug: b:383306740
Change-Id: I35ca017edf352efe4e66a5cfbd2879ab73d8a0f6

av1/encoder/encodeframe.c

diff --git a/av1/encoder/encodeframe.c b/av1/encoder/encodeframe.c
index 6095c47..215b571 100644
--- a/av1/encoder/encodeframe.c
+++ b/av1/encoder/encodeframe.c
@@ -549,6 +549,11 @@
         x->content_state_sb.source_sad_nonrd < kLowSad) {
       bsize_select = cm->seq_params->sb_size;
     }
+    if (cpi->sf.rt_sf.skip_encoding_non_reference_slide_change &&
+        cpi->rc.high_source_sad && cpi->ppi->rtc_ref.non_reference_frame) {
+      bsize_select = cm->seq_params->sb_size;
+      x->force_zeromv_skip_for_sb = 1;
+    }
     const BLOCK_SIZE bsize = seg_skip ? sb_size : bsize_select;
     if (x->content_state_sb.source_sad_nonrd > kZeroSad)
       x->force_color_check_block_level = 1;