Merge "Upgrade libpng to v1.6.43" into main am: f81d8a61d8 am: 7c3a90dc60

Original change: https://android-review.googlesource.com/c/platform/external/libpng/+/3132653

Change-Id: I2840c3f2b765d0934d84fdee9ff38ee652d8fd0e
Signed-off-by: Automerger Merge Worker <[email protected]>