Partially revert "[Settings] Start SettingsDumpService to dump the db log after the db is"

'Start SettingsDumpService after the MobileNetworkRepository is
created' sends the intent every single time the
NetworkDashboardFragment is instantiated (basically every time user
opens the network dashboard in Settings).

SettingsDumpService's lifecycle never finishes, since it's context is
passed to the MobileNetworkRepository for singleton instance creation
which then proceeds to holding a reference to that context thus keeping
the entire service alive along with the application process, which
prevents the static singleton from being garbage collected creating an
indirect retention cycle. All that over time grows into a solid memory
leak.

SettingsDumpService (as well as MobileNetworkRepository instance,
obviously) proceed to dangling until the app process gets eventually
killed by the lmkd (which is unlikely to happen but still was observed
on several devices running stock ROM) or manually terminated by user,
but based on the observation, maximum time of dangling could be
perfectly equal to global system uptime.

This issue still remains all the way up to latest AOSP tags and betas,
although some vendors stock ROMs seem to have sorted it out.

Since we don't really care about dumping mobile network info
(especially in production builds), do the minimum changes required to
remove the dumping feature and avoid future AOSP merge conflicts.

This partially reverts commit d6f3ad91.

Change-Id: Ifd7ded6cebd5f247cbdeb88035fdeb21cf060412