renaming or removing some image resources

app/src/main/AndroidManifest.xml

@@ -7,7 +7,7 @@
 
     <application
         android:allowBackup="true"
-        android:icon="@mipmap/launcher"
+        android:icon="@mipmap/ic_launcher"
         android:label="@string/app_launcher_name"
         android:supportsRtl="true"
         android:theme="@style/AppTheme">

app/src/main/java/com/simplemobiletools/draw/activities/MainActivity.java

@@ -329,11 +329,7 @@ public class MainActivity extends SimpleActivity implements MyCanvas.PathsChange
     }
 
     private void setBackgroundColor(int pickedColor) {
-        if (Utils.shouldUseWhite(pickedColor)) {
+        ((ImageView) mUndoBtn).setImageResource(R.drawable.ic_undo);
-            ((ImageView) mUndoBtn).setImageResource(R.mipmap.undo_white);
-        } else {
-            ((ImageView) mUndoBtn).setImageResource(R.mipmap.undo_black);
-        }
         mMyCanvas.setBackgroundColor(pickedColor);
     }
 

app/src/main/res/layout/activity_main.xml

@@ -23,7 +23,7 @@
         android:layout_alignParentRight="true"
         android:layout_below="@id/color_picker"
         android:padding="@dimen/medium_margin"
-        android:src="@mipmap/undo_black"
+        android:src="@drawable/ic_undo"
         android:visibility="gone"/>
 
     <SeekBar

app/src/main/res/menu/menu.xml

@@ -3,17 +3,17 @@
       xmlns:app="http://schemas.android.com/apk/res-auto">
     <item
         android:id="@+id/menu_save"
-        android:icon="@mipmap/save"
+        android:icon="@drawable/ic_save"
         android:title="@string/save"
         app:showAsAction="ifRoom"/>
     <item
         android:id="@+id/clear"
-        android:icon="@mipmap/ic_clear"
+        android:icon="@drawable/ic_clear"
         android:title="@string/clear"
         app:showAsAction="ifRoom"/>
     <item
         android:id="@+id/menu_share"
-        android:icon="@mipmap/share"
+        android:icon="@drawable/ic_share"
         android:title="@string/share"
         app:showAsAction="ifRoom"/>
     <item