MSIM: Use single baseband version for all SUB's

Issue: while updating base band version to  property in TSTS
 it exceeds the property value length and causes phone app crash.

Fix: Base band version is same for all SUB's, so no need of
 combining baseband versions with comma separator in MSIM and use
 super.setSystemProperty to overcome the setSystemProperty overid
 in MSIM files.

Change-Id: I093631d1cc92d950ff4b6f88d947c8ec42bc54c6
CRs-Fixed: 645033