Root Cause: systemServer's class path is not set
after set wrap.system_server property, and restart system_server,
it shows a java.lang.RuntimeException:
Missing class when invoking static main com.android.server.SystemServer
Solution: Correctly pass and parse a passed classpath.
Bug: 34692265
Test: adb root && adb shell stop && adb shell setprop wrap.system_server logwrapper && adb shell start
Change-Id: Ia6707dc05fa627af6cc28360d26b894487a6eff1