Update installation-android.md (#926)

docs/installation-android.md

 	    compile "com.facebook.react:react-native:+"
 	    compile project(':react-native-navigation')
 }
-```
 
 3. Your `MainActivity` should extend `com.reactnativenavigation.controllers.SplashActivity` instead of `ReactActivity`. If you have any `react-native` related methods in your `MainActivity` you can safely delete them.
 
 	    }
 	}
 	```
-6. Run react-native start
+6. Run react-native start