Enable dexopt for system server dex files

Add logic for dexopt-ing system server dex files. The files
are managed by the DexManager and need special dexopt
arguments.

As such, they have a dedicated dexopt path, that can be
initiated from DexManager. (The arguments are what we currently
use in ZygoteInit#performSystemServerDexOpt)

Test: adb shell cmd package dexopt android
      presubmits
Bug: 148774920
Change-Id: If0c0457f8045e8f475815136fb5ae2f340eb6661