Replace alphabetical order PNGs with a vector drawable.

app/src/main/java/org/fdroid/fdroid/views/apps/AppListActivity.java

@@ -117,11 +117,10 @@ public class AppListActivity extends AppCompatActivity implements LoaderManager.
             public void onClick(View view) {
                 if (sortClauseSelected.equalsIgnoreCase(SortClause.LAST_UPDATED)) {
                     sortClauseSelected = SortClause.NAME;
-                    if (FDroidApp.isAppThemeLight()) {
+                    final Drawable alphabetical = DrawableCompat.wrap(
-                        sortImage.setImageResource(R.drawable.ic_az_black);
+                            ContextCompat.getDrawable(AppListActivity.this, R.drawable.ic_sort_by_alpha)).mutate();
-                    } else {
+                    DrawableCompat.setTint(alphabetical, FDroidApp.isAppThemeLight() ? Color.BLACK : Color.WHITE);
-                        sortImage.setImageResource(R.drawable.ic_az_white);
+                    sortImage.setImageDrawable(alphabetical);
-                    }
                 } else {
                     sortClauseSelected = SortClause.LAST_UPDATED;
                     sortImage.setImageDrawable(lastUpdated);

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

@@ -0,0 +1,5 @@
+<vector android:height="24dp" android:tint="#FFFFFF"
+    android:viewportHeight="24" android:viewportWidth="24"
+    android:width="24dp" xmlns:android="http://schemas.android.com/apk/res/android">
+    <path android:fillColor="#FFFFFF" android:pathData="M14.94,4.66h-4.72l2.36,-2.36zM10.25,19.37h4.66l-2.33,2.33zM6.1,6.27L1.6,17.73h1.84l0.92,-2.45h5.11l0.92,2.45h1.84L7.74,6.27L6.1,6.27zM4.97,13.64l1.94,-5.18 1.94,5.18L4.97,13.64zM15.73,16.14h6.12v1.59h-8.53v-1.29l5.92,-8.56h-5.88v-1.6h8.3v1.26l-5.93,8.6z"/>
+</vector>