Move DreamManagerService to its own package.

Bug: 7204211
Change-Id: Ia6cfe252647161df357a4de149a06fa1e3fd63fa
diff --git a/services/java/com/android/server/SystemServer.java b/services/java/com/android/server/SystemServer.java
index eeab757..10f6961 100644
--- a/services/java/com/android/server/SystemServer.java
+++ b/services/java/com/android/server/SystemServer.java
@@ -51,6 +51,7 @@
 import com.android.server.am.ActivityManagerService;
 import com.android.server.am.BatteryStatsService;
 import com.android.server.display.DisplayManagerService;
+import com.android.server.dreams.DreamManagerService;
 import com.android.server.input.InputManagerService;
 import com.android.server.net.NetworkPolicyManagerService;
 import com.android.server.net.NetworkStatsService;