Removed erroneous selector from selected navigation item background in pre-lollipop versions.

Author: eeVoskos

android/src/main/res/drawable-v21/selected_navdrawer_item_background.xml

@@ -0,0 +1,23 @@
+<!--
+  Copyright 2014 Google Inc. All rights reserved.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+  -->
+<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
+    <item>
+        <shape>
+            <solid android:color="#12000000" />
+        </shape>
+    </item>
+    <item android:drawable="?android:selectableItemBackground" />
+</layer-list>

android/src/main/res/drawable/selected_navdrawer_item_background.xml

@@ -13,11 +13,6 @@
   See the License for the specific language governing permissions and
   limitations under the License.
   -->
-<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
-    <item>
-        <shape>
-            <solid android:color="#12000000" />
-        </shape>
-    </item>
-    <item android:drawable="?android:selectableItemBackground" />
-</layer-list>
+<shape xmlns:android="http://schemas.android.com/apk/res/android">
+    <solid android:color="#12000000" />
+</shape>