We don't build libxsec_xmlsec for Android currently

(Because we don't build NSS for Android, so it would be pointless to build
libxsec_xmlsec. Or something like that. No doubt at some stage somebody will
get the great idea that we need to build NSS for Android, too. But postpone
the pain.)

Python experts, feel free to generate the ifdefs in this script in a more
elegant fashion. Surely it would be better to somehow mark those entries in
the table that should be optional with the corresponding condition, instead of
hardcoding tests for 'sb_component_getFactory' and
'xsec_xmlsec_component_getFactory' in four places.

Change-Id: I69255ab4966605849a2f3335d45a2bc0366f3ab9