Fix solid circle show on message notification

Message app or other apps will use some format code or controll
code on SenderName to fit RTL or other design, and symbols will
produced by these code. The special code pattern not include these
code, so it will go charIcon flow.
Although these code is not visible, we should just ignore them to
get symbol strings

Change-Id: I20ef459b10ba7504ec0c997ed815cb485817d2bc
Fixes: 109746235
Test: Check notification form message app on RTL
Test: atest SystemUITests