Resurrect app prediciton sessions after destroy and rebind

After App Prediction service restarts, existing app prediction sessions
will be inactive and needs to be resurrected.

Test: flash to physical device and
1. Open a couple of Personal Profile and Work Profile apps and observe
that they make it to the prediction row.
2. Clear storage via the Settings > Privacy > Device Personalization
Services > Personal > Clear data > All time
3. Verify prediction row should start getting updated again for
subsequently opened apps
Bug: 146802640

Change-Id: I74d87e374806b92649a9a3436926fb5bd5572874

services/appprediction/java/com/android/server/appprediction/AppPredictionPerUserService.java

@@ -267,6 +267,9 @@ public class AppPredictionPerUserService extends
         mRemoteService.destroy();
         mRemoteService = null;
 
+        synchronized (mLock) {
+            mZombie = true;
+        }
         mRemoteService = getRemoteServiceLocked();
         if (mRemoteService != null) {
             if (isDebug()) {