Moved Android specific logger to separate plugin.

This is mainly because the other parts of the existing android plugin
can not be built in the NDK (access to keystore and system properties are
not part of the stable NDK libraries).

man/strongswan.conf.5.in

@@ -272,7 +272,7 @@ Section to define syslog loggers, see LOGGER CONFIGURATION
 Number of worker threads in charon
 .SS charon.plugins subsection
 .TP
-.BR charon.plugins.android.loglevel " [1]"
+.BR charon.plugins.android_log.loglevel " [1]"
 Loglevel for logging to Android specific logger
 .TP
 .BR charon.plugins.attr