Merge "Use static_cast for NULL to pointer type" am: d77ad7e9dc am: 459740c167 am: 06a513ba98 am: b2d45ff546

Original change: https://android-review.googlesource.com/c/platform/external/sfntly/+/1945422

Change-Id: Icb1e1438f44bb57209247b1dcd972e52990a9cc8