Only show Taskbar Edu once (first time an app is opened).

Bug: 180605356
Test: Manual
Change-Id: I2cc102d7ce36e0b1c2c75482e2bbb97218618e61
diff --git a/quickstep/src/com/android/launcher3/taskbar/LauncherTaskbarUIController.java b/quickstep/src/com/android/launcher3/taskbar/LauncherTaskbarUIController.java
index b2e33eb..4c96fba 100644
--- a/quickstep/src/com/android/launcher3/taskbar/LauncherTaskbarUIController.java
+++ b/quickstep/src/com/android/launcher3/taskbar/LauncherTaskbarUIController.java
@@ -35,6 +35,7 @@
 import com.android.launcher3.config.FeatureFlags;
 import com.android.launcher3.util.MultiValueAlpha;
 import com.android.launcher3.util.MultiValueAlpha.AlphaProperty;
+import com.android.launcher3.util.OnboardingPrefs;
 import com.android.quickstep.AnimatedFloat;
 import com.android.quickstep.RecentsAnimationCallbacks;
 import com.android.quickstep.RecentsAnimationCallbacks.RecentsAnimationListener;
@@ -266,9 +267,11 @@
      * Starts the taskbar education flow, if the user hasn't seen it yet.
      */
     public void showEdu() {
-        if (!FeatureFlags.ENABLE_TASKBAR_EDU.get()) {
+        if (!FeatureFlags.ENABLE_TASKBAR_EDU.get()
+                || mLauncher.getOnboardingPrefs().getBoolean(OnboardingPrefs.TASKBAR_EDU_SEEN)) {
             return;
         }
+        mLauncher.getOnboardingPrefs().markChecked(OnboardingPrefs.TASKBAR_EDU_SEEN);
 
         mControllers.taskbarEduController.showEdu();
     }
diff --git a/src/com/android/launcher3/util/OnboardingPrefs.java b/src/com/android/launcher3/util/OnboardingPrefs.java
index 40bc9c3..cf1467a 100644
--- a/src/com/android/launcher3/util/OnboardingPrefs.java
+++ b/src/com/android/launcher3/util/OnboardingPrefs.java
@@ -38,6 +38,7 @@
     public static final String HOTSEAT_LONGPRESS_TIP_SEEN = "launcher.hotseat_longpress_tip_seen";
     public static final String SEARCH_EDU_SEEN = "launcher.search_edu_seen";
     public static final String SEARCH_SNACKBAR_COUNT = "launcher.keyboard_snackbar_count";
+    public static final String TASKBAR_EDU_SEEN = "launcher.taskbar_edu_seen";
 
     /**
      * Events that either have happened or have not (booleans).
@@ -45,7 +46,8 @@
     @StringDef(value = {
             HOME_BOUNCE_SEEN,
             HOTSEAT_LONGPRESS_TIP_SEEN,
-            SEARCH_EDU_SEEN
+            SEARCH_EDU_SEEN,
+            TASKBAR_EDU_SEEN
     })
     @Retention(RetentionPolicy.SOURCE)
     public @interface EventBoolKey {