Adding launch source info in the wallpaper picker intent (1/3)

When launching Wallpaper & Style from the settings search, we should
also append the launch source information to the intent.

The major purpose if for logging. So that we know then entrypoint of the
Wallpaper & Style app.

Test: Manually tested that the intent contains the extra we need
Bug: 368052505
Flag: EXEMPT bugfix
Change-Id: I9af663dad7cb79bfe74431e6a61cd34393e60dbd

tests/robotests/src/com/android/settings/wallpaper/WallpaperSuggestionActivityTest.java

@@ -118,7 +118,7 @@ public class WallpaperSuggestionActivityTest {
     }
 
     @Test
-    public void addExtras_intentNotFromSetupWizard_extrasHasFocusWallpaper() {
+    public void addExtras_intentNotFromSetupWizard_extrasHasFocusWallpaperAndLaunchedSettingsSearch() {
         WallpaperSuggestionActivity activity = Robolectric.buildActivity(
                 WallpaperSuggestionActivity.class, new Intent(Intent.ACTION_MAIN).setComponent(
                         new ComponentName(RuntimeEnvironment.application,
@@ -127,6 +127,8 @@ public class WallpaperSuggestionActivityTest {
 
         assertThat(intent).isNotNull();
         assertThat(intent.getStringExtra(WALLPAPER_FLAVOR)).isEqualTo("focus_wallpaper");
+        assertThat(intent.getStringExtra(WALLPAPER_LAUNCH_SOURCE))
+                .isEqualTo("app_launched_settings_search");
     }