Do not duplicate android_log_write output to GC log file (Android)

Do not duplicate android_log_write output to GC log file (Android)

* include/private/gc_priv.h (GC_real_print_stats): Remove macro.
* include/private/gc_priv.h (GC_print_stats): Define as external
variable (instead of a macro) for GC_ANDROID_LOG (only if not
SMALL_CONFIG).
* misc.c (GC_real_print_stats, GC_init): Replace GC_real_print_stats
back to GC_print_stats.
* misc.c (GC_printf, GC_LOG_PRINTF_IMPL, GC_warn_printf, GC_err_puts):
Do not duplicate output to GC_stdout/err, GC_log if GC_ANDROID_LOG
(after calling __android_log_write).
* misc.c (GC_LOG_PRINTF_IMPL): Remove unused "fileLogCond" argument.
* misc.c (GC_default_warn_proc): Do not duplicate output to
GC_stderr if GC_ANDROID_LOG (before __android_log_assert invocation).