utf8conv.c: Add hacks for Android.
* common/utf8conv.c [HAVE_ANDROID_SYSTEM]: Do not include iconv.h. (iconv_open, iconv_close, load_libiconv) [HAVE_ANDROID_SYSTEM]: New dummy functions. (set_native_charset) [HAVE_ANDROID_SYSTEM]: Force use of "utf-8". (jnlib_iconv_open) [HAVE_ANDROID_SYSTEM]: Act the same as under W32. (jnlib_iconv) [HAVE_ANDROID_SYSTEM]: Ditto. (jnlib_iconv_close) [HAVE_ANDROID_SYSTEM]: Ditto.
- Co-authored-by: Hans of Guardian <hans@guardianproject.info>