MapbMessage: Apply pattern matching

str.split(regex, n) is the same as Pattern.compile(regex).split(str, n).
Except that the second can be compiled once why the first need to be
recompile everytime it is invoked

Bug: 371471052
Flag: Exempt refactor
Test: atest BluetoothInstrumentationTests
Change-Id: Iccfad5430d292ff5082b3701ac48383aab7ed5e2