And replace the plugin with instructions for rebuilding the .aar files
for the bind and ivy examples.
While here, fix a compile error in the Ivy example caused by gomobile
no longer prepending org.golang. to its generated Java packages by
default.
Fixesgolang/go#25314Fixesgolang/go#28098Fixesgolang/go#25184
Change-Id: Iaccdd50850a185414ebcf21427cfd7f625c6a298
Reviewed-on: https://go-review.googlesource.com/c/141057
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
