Implement the CarrierConfig for call indicators

This CL implements the CarirerConfigs for both no calling icons and call
strength icons.
1. Carriers can choose to only show the no calling icons when there is
no IP connections.
2. Carriers can choose to hide the call strength icon, and show either a
blacnk icon (single SIM) or SIM card icon (multi SIM)

Bug: 181667933
Test: Manual tests
Change-Id: I54386cb7399c7e3b3160ad01e09cb71f7e1f1a6e
Merged-In: I54386cb7399c7e3b3160ad01e09cb71f7e1f1a6e