Add intent extra when launching WallpaperPicker from Launcher

 - Add extra to the intent to help WallpaperPicker log the launch
 source
 - design doc: go/log-wppg-launch-source

Bug: 154781896
Test: manually
Change-Id: Ife774866b06251c01f28f72555c3dcc844fdc051
diff --git a/src/com/android/launcher3/Utilities.java b/src/com/android/launcher3/Utilities.java
index bf63788..681118d 100644
--- a/src/com/android/launcher3/Utilities.java
+++ b/src/com/android/launcher3/Utilities.java
@@ -141,6 +141,10 @@
     public static final String EXTRA_WALLPAPER_OFFSET = "com.android.launcher3.WALLPAPER_OFFSET";
     public static final String EXTRA_WALLPAPER_FLAVOR = "com.android.launcher3.WALLPAPER_FLAVOR";
 
+    // An intent extra to indicate the launch source by launcher.
+    public static final String EXTRA_WALLPAPER_LAUNCH_SOURCE =
+            "com.android.wallpaper.LAUNCH_SOURCE";
+
     public static boolean IS_RUNNING_IN_TEST_HARNESS =
                     ActivityManager.isRunningInTestHarness();
 
diff --git a/src/com/android/launcher3/views/OptionsPopupView.java b/src/com/android/launcher3/views/OptionsPopupView.java
index d558781..349ba9d 100644
--- a/src/com/android/launcher3/views/OptionsPopupView.java
+++ b/src/com/android/launcher3/views/OptionsPopupView.java
@@ -16,6 +16,7 @@
 package com.android.launcher3.views;
 
 import static com.android.launcher3.Utilities.EXTRA_WALLPAPER_FLAVOR;
+import static com.android.launcher3.Utilities.EXTRA_WALLPAPER_LAUNCH_SOURCE;
 import static com.android.launcher3.Utilities.EXTRA_WALLPAPER_OFFSET;
 import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.IGNORE;
 import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_SETTINGS_BUTTON_TAP_OR_LONGPRESS;
@@ -210,7 +211,8 @@
         Intent intent = new Intent(Intent.ACTION_SET_WALLPAPER)
                 .addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK)
                 .putExtra(EXTRA_WALLPAPER_OFFSET,
-                        launcher.getWorkspace().getWallpaperOffsetForCenterPage());
+                        launcher.getWorkspace().getWallpaperOffsetForCenterPage())
+                .putExtra(EXTRA_WALLPAPER_LAUNCH_SOURCE, "app_launched_launcher");
         if (!Utilities.existsStyleWallpapers(launcher)) {
             intent.putExtra(EXTRA_WALLPAPER_FLAVOR, "wallpaper_only");
         } else {