Move the net transition wakelock to ConnService.

When the default network goes down we lose the wake-on-incoming-data capability
until the new net is brought up and apps rebuild their connections.  We fixed this
in Wifi, but it's a general connectivity issue, not a wifi issue so moving the
mechanism to connecitivty so other networks can use it.

bug:2734419
Change-Id: I39b5d825eb6b548bd9bb8f179b89254f4db53147

core/java/android/net/ConnectivityManager.java

@@ -524,5 +524,20 @@ public class ConnectivityManager
         } catch (RemoteException e) {
             return TETHER_ERROR_SERVICE_UNAVAIL;
         }
-   }
+    }
+
+    /**
+     * Ensure the device stays awake until we connect with the next network
+     * @param forWhome The name of the network going down for logging purposes
+     * @return {@code true} on success, {@code false} on failure
+     * {@hide}
+     */
+    public boolean requestNetworkTransitionWakelock(String forWhom) {
+        try {
+            mService.requestNetworkTransitionWakelock(forWhom);
+            return true;
+        } catch (RemoteException e) {
+            return false;
+        }
+    }
 }

core/java/android/net/IConnectivityManager.aidl

@@ -72,4 +72,6 @@ interface IConnectivityManager
     String[] getTetherableUsbRegexs();
 
     String[] getTetherableWifiRegexs();
+
+    void requestNetworkTransitionWakelock(in String forWhom);
 }