Remove system_server classes from the boot image.

We set the system_server classpath in the environment
(like we do with BOOTCLASSPATH). After the zygote forks
the system_server, we dexopt the classpath (if needed)
and then launch the system server with the correct
PathClassLoader. This needed several small / medium
refactorings :

- The logic for connecting to installd is now in a separate
  class and belongs in the system_server.
- SystemService / SystemServiceManager have now moved to
  classes.jar. They are only used from there, and since they
  use Class.forName, we want them to be loaded by the
  system_server classloader, and not the bootclassloader.
- BootReceiver now moves to frameworks.jar, because it is
  used by ActivityThread and friends.

bug: 16555230

Change-Id: Ic84f0b2baf611eeedff6d123cb7191bb0259e600
diff --git a/services/devicepolicy/Android.mk b/services/devicepolicy/Android.mk
index a55d138..7020f17 100644
--- a/services/devicepolicy/Android.mk
+++ b/services/devicepolicy/Android.mk
@@ -7,6 +7,6 @@
 LOCAL_SRC_FILES += \
       $(call all-java-files-under,java)
 
-LOCAL_JAVA_LIBRARIES := conscrypt
+LOCAL_JAVA_LIBRARIES := conscrypt services.core
 
 include $(BUILD_STATIC_JAVA_LIBRARY)