Remove vendor_available from cargo2android.json. am: 43a62263d0 am: ae9ec6a74f am: 5b2c645c3a

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/libloading/+/2834510

Change-Id: I533d3b596420eb90f160301bfb5c05984363ceff
Signed-off-by: Automerger Merge Worker <[email protected]>