Fixed error with rendering color in api<21

app/src/main/java/srct/whatsopen/views/activities/DetailActivity.java

@@ -3,6 +3,8 @@ package srct.whatsopen.views.activities;
 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
+import android.graphics.Color;
+import android.graphics.PorterDuff;
 import android.os.Build;
 import android.os.Bundle;
 import android.os.Handler;
@@ -14,6 +16,7 @@ import android.support.v7.app.AppCompatActivity;
 import android.support.v7.widget.Toolbar;
 import android.text.Html;
 import android.transition.Slide;
+import android.view.Display;
 import android.view.Gravity;
 import android.view.Menu;
 import android.view.MenuItem;

app/src/main/res/drawable/ic_fav_button_off_24dp.xml

@@ -4,6 +4,6 @@
         android:viewportWidth="24.0"
         android:viewportHeight="24.0">
     <path
-        android:fillColor="@color/favoriteButtonOff"
+        android:fillColor="#757575"
         android:pathData="M12,17.27L18.18,21l-1.64,-7.03L22,9.24l-7.19,-0.61L12,2 9.19,8.63 2,9.24l5.46,4.73L5.82,21z"/>
 </vector>

app/src/main/res/drawable/ic_fav_button_on_24dp.xml

@@ -4,6 +4,6 @@
         android:viewportWidth="24.0"
         android:viewportHeight="24.0">
     <path
-        android:fillColor="@color/favoriteButtonOn"
+        android:fillColor="#E8B827"
         android:pathData="M12,17.27L18.18,21l-1.64,-7.03L22,9.24l-7.19,-0.61L12,2 9.19,8.63 2,9.24l5.46,4.73L5.82,21z"/>
 </vector>