Merge "Use 0 instead of NULL for comparison to char16_t" am: 6a79e8113a am: dc4af935d5 am: 1901114704 am: 41ad47e55a

Original change: https://android-review.googlesource.com/c/platform/system/core/+/1949458

Change-Id: If3a58bde6277971e7289eecef25b7f015d75b0bc