Enable vendor Telephony plugin: MSIM Changes

Author: Sneh Bansal <snehb@codeaurora.org>
Date:   Fri Jan 19 17:18:32 2018 +0530

    Enable vendor Telephony plugin: MSIM Changes

    MSIM Changes that are needed to enable vendor telephony framework.

    CRs-Fixed: 2172757
    Change-Id: I80a46de96c34d5e2a4ce952830f6beb862522de5

Author: Sandeep Gutta <sangutta@codeaurora.org>
Date:   Mon Feb 12 13:56:27 2018 +0530

    MSIM: Perform code clean-up

    Make required changes to use vanilla implementation for
    handling SIM ERROR scenario.

    Change few method access specifiers and remove unused constant.

    Change-Id: Ifffc1cbff72316ec6885e0f4eb0a7b89dadcc96d
    CRs-Fixed: 2179165

Change-Id: I1df4fcacea64a09c0720109fa2547e4f0cbbf43b