Remove the "android" package from dexopting.

We no longer allow dexopting the system server, so we need to ensure it
isn't added to the list of packages to dexopt.

Test: adb shell pm compile -m speed-profile -f -a
  with dalvik.vm.useartservice=false
Bug: 274576247
Change-Id: I9da100987e611e59ac6ef2282bf0221d9417bc9a