Revert "build(libcore): gomobile no longer supports the 'cache' param…

…eter"

This reverts commit f778b06.

libcore/build.sh

@@ -9,7 +9,7 @@ rm -rf $BUILD/android \
   $BUILD/javac-output \
   $BUILD/src
 
-gomobile bind -v -androidapi 21 -trimpath -ldflags='-s -w' -tags='with_conntrack,with_gvisor,with_quic,with_wireguard,with_utls,with_clash_api,with_ech' . || exit 1
+gomobile bind -v -androidapi 21 -cache $(realpath $BUILD) -trimpath -ldflags='-s -w' -tags='with_conntrack,with_gvisor,with_quic,with_wireguard,with_utls,with_clash_api,with_ech' . || exit 1
 rm -r libcore-sources.jar
 
 proj=../app/libs