Save picker behavior related to launch and apply

- Define key for SharedPreference.
 KEY_APP_LAUNCH_COUNT
 KEY_FIRST_LAUNCH_DATE_SINCE_SETUP
 KEY_FIRST_WALLPAPER_APPLY_DATE_SINCE_SETUP
- Save picker launch count and first launch date.
- Save wallpaper first apply date.

Test: Manual
Bug: 151130766
Change-Id: Id332d97f49763b65d3279e7d1ca5584dd7c38661
diff --git a/src/com/android/wallpaper/picker/TopLevelPickerActivity.java b/src/com/android/wallpaper/picker/TopLevelPickerActivity.java
index 482b77e..d0731e9 100755
--- a/src/com/android/wallpaper/picker/TopLevelPickerActivity.java
+++ b/src/com/android/wallpaper/picker/TopLevelPickerActivity.java
@@ -108,6 +108,7 @@
     private NetworkStatusNotifier mNetworkStatusNotifier;
     private NetworkStatusNotifier.Listener mNetworkStatusListener;
     private WallpaperPersister mWallpaperPersister;
+    private WallpaperPreferences mWallpaperPreferences;
     private boolean mWasCustomPhotoWallpaperSet;
     @WallpaperPosition
     private int mCustomPhotoWallpaperPosition;
@@ -305,6 +306,7 @@
         if (fragment == null) {
             // App launch specific logic: log the "app launched" event and set up daily logging.
             mUserEventLogger.logAppLaunched();
+            mWallpaperPreferences.incrementAppLaunched();
             DailyLoggingAlarmScheduler.setAlarm(getApplicationContext());
 
             CategoryFragment newFragment = CategoryFragment.newInstance(
@@ -367,6 +369,7 @@
         if (fragment == null) {
             // App launch specific logic: log the "app launched" event and set up daily logging.
             mUserEventLogger.logAppLaunched();
+            mWallpaperPreferences.incrementAppLaunched();
             DailyLoggingAlarmScheduler.setAlarm(getApplicationContext());
         }