mobile: don't retain transient []byte in CallMsg.SetData (#14804)

* mobile: don't retain transient []byte in CallMsg.SetData

Go mobile doesn't copy []byte parameters, for performance and to allow
writes to the byte array be reflected in the native byte array.
Unfortunately, that means []byte arguments are only valid during the
call it is being passed into.

CallMsg.SetData retains such a byte array. Copy it instead

Fixes #14675

* mobile: copy all []byte arguments from gomobile

To avoid subtle errors when accidentially retaining an otherwise
transient byte slice coming from gomobile, copy all byte slices before
use.

* mobile: replace copySlice with common.CopyBytes

mobile/bind.go

@@ -119,7 +119,7 @@ func DeployContract(opts *TransactOpts, abiJSON string, bytecode []byte, client
 	if err != nil {
 		return nil, err
 	}
-	addr, tx, bound, err := bind.DeployContract(&opts.opts, parsed, bytecode, client.client, args.objects...)
+	addr, tx, bound, err := bind.DeployContract(&opts.opts, parsed, common.CopyBytes(bytecode), client.client, args.objects...)
 	if err != nil {
 		return nil, err
 	}