DynaLoader: On Android, define DLOPEN_WONT_DO_RELATIVE_PATHS

DynaLoader: On Android, define DLOPEN_WONT_DO_RELATIVE_PATHS

Android's linker will actually do relative paths just fine; the problem
is that it won't search from the current directory, only on
/vendor/lib, /system/lib, and whatever is in LD_LIBRARY_PATH.
While the core handles that just fine, bits of CPAN rather rightfully
expect this to work:

use lib 'foo'            # puts foo/ in @INC
use My::Module::In::Foo; # calls dlopen() with foo/My/Module/...
                         # which will likely fail

So we take this route instead.