bluez5: fix CVE-2022-0204

Fix heap overflow when appending prepare writes

The code shall check if the prepare writes would append more the
allowed maximum attribute length.

Upstream-Status: Backport [https://github.com/bluez/bluez/commit/591c546c536b42bef696d027f64aa22434f8c3f0

]
CVE: CVE-2022-0204

Signed-off-by: Ralph Siemsen <ralph.siemsen@linaro.org>
Signed-off-by: Steve Sakoman <steve@sakoman.com>