4373 & 4374 part of Severe Alerts

As per specification change 23.041 V9.6.0,
4373 & 4374 have been moved from Extreme
Alerts to Severe Alerts
CRs-Fixed: 461890

Change-Id: I0c956507c3ac2fb864b6d228d827a7f0063dd7a0
CellBroadcastReceiver(MSIM): Extend CB "Operator info" feature to MSIM

1) Add SUB information while broadcasting CB intent for MSIM.
2) Remove country specific checks for cellbroadcast Operator
   info for MSIM.
3) Move Operator info to About phone->Status->SelectSubscription
   ->SUB1/SUB2->Operator info in MSIM
CRs-fixed: 498245

Change-Id: Icd619b0a2b04d275646528a17427a6e1c721aede
Use proper check to detect duplicates for CMAS messages

As per spec 3GPP 23.041, in order to determine a
duplicate, combination of message identifier,
serial number and PLMN should be used.
CRs-Fixed: 472577

Change-Id: I59d2a828bc7a7a9e42a460168521a5641799dd76
CB: Add system property to enable/disable dup detection

If system property persist.cb.dup_detection is set to false, duplicate
detection is disabled.  If it is set to true, duplicate detection is
enabled.  If the system property does not exist, using true/enabled
as a default value.

Change-Id: If377675c46950b4a03253fa29c2d8ae1c5804544
CellBroadCast(DSDS): Support for cellbroadcast in DSDS

Configure GSM CB MsgId 50 on power up for DSDS.
Change to enable/disable CB message 50 as per user preference.

Change-Id: I0a4f608f8136fa0d88572a17c60e146bb593519a
Merge "CellBroadCast(DSDS): Support for cellbroadcast in DSDS"
Merge branch 'jb_mr2' of git://codeaurora.org/platform/packages/apps/CellBroadcastReceiver into qcril
Merge remote-tracking branch 'cm/cm-10.2' into qcril