Add support for selectionColor on Android TextInput

Summary:
public
This adds support to set the highlight color on TextInput on Android.  See https://github.com/facebook/react-native/pull/5678 for the iOS implementation.

Note : We will merge these two properties with one name 'selectionColor' in a follow on diff, and may move it to a style.

Reviewed By: nicklockwood

Differential Revision: D2895253

fb-gh-sync-id: 6f2c08c812ff0028973185356a8af285f7dd7969

Examples/UIExplorer/TextInputExample.android.js

@@ -322,6 +322,11 @@ exports.examples = [
               Darker backgroundColor
             </Text>
           </TextInput>
+          <TextInput
+            defaultValue="Highlight Color is red"
+            selectionColor={'red'}
+            style={styles.singleLine}>
+          </TextInput>
         </View>
       );
     }