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

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

Change-Id: I1095a1f57d4a91628f5ea8a2c7bdfb8c503eea19