Currently, after `CONFIG_LWM2M_RD_CLIENT_SUPPORT_BOOTSTRAP` is enabled,
the LwM2M engine will initiate bootstrap procedure on each run. This
approach limits the flexibility of the application, as it's not always
necessary to go over the bootstrap procedure (for instance, the
application may decide to store the security object obtained during the
bootstrap in flash, and restore it on boot).
Fix this by introducing an additional `flags` parameter to the
`lwm2m_rd_client_start()` function, which provides information whether
to run bootstrap in the current session or not.
Signed-off-by: Robert Lubos <robert.lubos@nordicsemi.no>
f7a5638871