Forward wallpaper activity results to the caller.

- Added Activity.FLAG_ACTIVITY_FORWARD_RESULT to the intent that
launches the wallpaper activities.
- WallpaperSuggestionActivity also finishes itself after launching
intent.

Bug: 65691577
Test: Added robolectric test. Also verified manually that result code is
being forwarded
Change-Id: I2f8b0fac7a35c38e14c4a733b7552fd2e58dd0db

src/com/android/settings/wallpaper/WallpaperSuggestionActivity.java

@@ -51,9 +51,9 @@ public class WallpaperSuggestionActivity extends Activity {
     @VisibleForTesting
     void startFallbackSuggestion() {
         // fall back to default wallpaper picker
-        Utils.startWithFragment(this, WallpaperTypeSettings.class.getName(), null, null, 0,
-                R.string.wallpaper_suggestion_title, null,
-                MetricsProto.MetricsEvent.DASHBOARD_SUMMARY);
+        Utils.startWithFragment(this, WallpaperTypeSettings.class.getName(),
+                R.string.wallpaper_suggestion_title, MetricsProto.MetricsEvent.DASHBOARD_SUMMARY,
+                Intent.FLAG_ACTIVITY_FORWARD_RESULT);
     }
 
     @VisibleForTesting

src/com/android/settings/wallpaper/WallpaperTypeSettings.java

@@ -16,6 +16,7 @@
 
 package com.android.settings.wallpaper;
 
+import android.app.Activity;
 import android.content.ComponentName;
 import android.content.Context;
 import android.content.Intent;
@@ -67,7 +68,7 @@ public class WallpaperTypeSettings extends SettingsPreferenceFragment implements
         // Add Preference items for each of the matching activities
         for (ResolveInfo info : rList) {
             Preference pref = new Preference(getPrefContext());
-            Intent prefIntent = new Intent(intent);
+            Intent prefIntent = new Intent(intent).addFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT);
             prefIntent.setComponent(new ComponentName(
                     info.activityInfo.packageName, info.activityInfo.name));
             pref.setIntent(prefIntent);
@@ -79,6 +80,16 @@ public class WallpaperTypeSettings extends SettingsPreferenceFragment implements
         }
     }
 
+    @Override
+    public boolean onPreferenceTreeClick(Preference preference) {
+        if (preference.getIntent() == null) {
+            return super.onPreferenceTreeClick(preference);
+        }
+        startActivity(preference.getIntent());
+        finish();
+        return true;
+    }
+
     public static final SearchIndexProvider SEARCH_INDEX_DATA_PROVIDER =
         new BaseSearchIndexProvider() {
             @Override