Merge "Add explicit visibility." into main am: 3e397c7182 am: 3d8225cc40

Original change: https://android-review.googlesource.com/c/platform/external/giflib/+/3272411

Change-Id: Ie253b3c2c6fcc55b3aa9e3e313c54896068fa419
Signed-off-by: Automerger Merge Worker <[email protected]>