[MS06] Add carrier template fields into cloud backup/restore

NetworkTemplate with MATCH_CARRIER can be created in NPMS,
and can be backup by SettingsBackupAgent. However, since
the meteredness is not stored in the backup. After incorrectly
deducing from match rule, meteredness always becomes
METERED_ALL after restoring from backup.

This change also adds debug log if any non-persistable template
is being backed up.

Test: TH, dedicated test is included in the follow-up CL.
Bug: 204830222

Change-Id: I865b1d6e571ed998a75b776f01afc7c2534af2dc