Enable stack overflow recovery on Android

Enable stack overflow recovery on Android

* src/sysdep.c (handle_sigsegv): Return after restoring the
original signal handler, which should proceed to call debuggerd
to generate a tombstone.
(init_sigsegv): Save the original signal handler on Android, to
be restored after a signal is received.
(init_signals): Call init_sigsegv on Android.

(cherry picked from commit 5d9a8c3704c156cccea90a46362e6bfae0de87f2)