Phone: Add emergency call list setting feature

Enable the feature of emergency call setting, user can add/remove/edit
emergency call numbers with this feature.

Change-Id: I2e3a15fdd34a328373f53d802b18d4e42d56e6f5
Signed-off-by: anerikg <anerikgames@gmail.com>

Conflicts:
	res/values-zh-rCN/cm_strings.xml
Add config to control disable SUB2 apn.

When disable_data_sub2 is true in DSDS mode, disable apn of SUB0.

Change-Id: Ie10803e791e3cc3d3ba30c9d940f56feb3df7935
Phone: Add support for IP call prefix

Add a preference screen to edit IP call prefix, and add the
prefix when MO a IP call.

Change-Id: I258ee4b15a52ac7612fc72243db1f08d66bd71d0
Signed-off-by: anerikg <anerikgames@gmail.com>

Conflicts:
	res/values-zh-rCN/cm_strings.xml
Phone: Enable incremental search for PLMN

As per existing implementation Modem sends all the PLMN list information
in single request. once all the PLMN list is available then it is displayed
in UI.

As part of these changes Modem will send incremental PLMN list available
to telephony. When the list is available from Modem to telephony, the
PLMN list is displayed in UI.The UI gets refreshed with incremental PLMN
list whenever there is an indication from Modem.

Change-Id: I7aff3a28047f8fe98fdd1027c4da157d70f9f996