Upgrade rust/crates/libloading to 0.6.3 am: 32890e15d2 am: 1d3b6e97be

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/libloading/+/1408804

Change-Id: I7a01afe0065652ef0fe35cddf3847a03413b2663