Add null check to prevent crashes when logging

Changes instances of mSplitLayout.isLeftRightSplit() to use a version that has a null check.

This will prevent crashes when logging, but notably we will now log "false" in instances where SplitLayout is null, instead of crashing. I think this is probably an improvement, but maybe the logging system should be updated to take a non-boolean value so we can correctly log the edge case where SplitLayout is null.

Fixes: 407635924
Flag: EXEMPT bugfix
Test: EXEMPT logging changes only
Change-Id: I7e1a280a8f603cc2e5cab798bdda56167a9d7362