DefaultThemeProvider should support launcher icon packs

Bug: 126738409
Change-Id: I50c5c28fb1752bb66a1d25352098add5677e7cec
diff --git a/src/com/android/customization/model/theme/DefaultThemeProvider.java b/src/com/android/customization/model/theme/DefaultThemeProvider.java
index 3ba8f55..a841f87 100644
--- a/src/com/android/customization/model/theme/DefaultThemeProvider.java
+++ b/src/com/android/customization/model/theme/DefaultThemeProvider.java
@@ -65,6 +65,7 @@
     private static final String COLOR_PREFIX = "theme_overlay_color_";
     private static final String SHAPE_PREFIX = "theme_overlay_shape_";
     private static final String ICON_ANDROID_PREFIX = "theme_overlay_icon_android_";
+    private static final String ICON_LAUNCHER_PREFIX = "theme_overlay_icon_launcher_";
     private static final String ICON_SETTINGS_PREFIX = "theme_overlay_icon_settings_";
     private static final String ICON_SYSUI_PREFIX = "theme_overlay_icon_sysui_";
     private static final String ICON_PREVIEW_DRAWABLE_NAME = "ic_wifi_signal_3";
@@ -194,6 +195,13 @@
                     }
                 }
 
+                String iconLauncherOverlayPackage = getOverlayPackage(ICON_LAUNCHER_PREFIX,
+                        themeName);
+                if (!TextUtils.isEmpty(iconLauncherOverlayPackage)) {
+                    builder.addOverlayPackage(getOverlayCategory(iconLauncherOverlayPackage),
+                            iconLauncherOverlayPackage);
+                }
+
                 String iconSettingsOverlayPackage = getOverlayPackage(ICON_SETTINGS_PREFIX,
                         themeName);