Fix gamepad connected status on Android

Commit 667f0577 created a regression
in gamepad API functionality on Android by removing the assignment
that sets the gamepad.connected value. This CL adds the missing
assignment back.

BUG=644162

Review-Url: https://codereview.chromium.org/2350573002
Cr-Commit-Position: refs/heads/master@{#422947}

device/gamepad/gamepad_platform_data_fetcher_android.cc

@@ -117,6 +117,7 @@ static void SetGamepadData(JNIEnv* env,
     pad.mapping[mapping_to_copy] = 0;
   }
 
+  pad.connected = true;
   pad.timestamp = timestamp;
 
   std::vector<float> axes;