Add support for `LOCAL_SANITIZE := integer`.

This also does a bit of cleanup in config_sanitizers.mk. The result is
that `LOCAL_SANITIZE := <any arbitrary ubsan group>` should function
fine for both host and target.

This is a superset of LOCAL_DETECT_INTEGER_OVERFLOWS, so remove that.
This also checks integer division by zero.  It's supposed to cover
shifting undefined behaviors as well, but apparently it does not
(though `LOCAL_SANITIZE := shift` works fine).

Change-Id: I4ac99eafa6920a3f8cb82af37ce56ff0fdb95223