Forward fix for: Set FLAG_IMMUTABLE flag on FirstScreenBroadcast PendingIntent.

Bug: 179289753
Bug: 183927137
Test: restore phone and ensure broadcast is sent

Change-Id: I60e179d35957309f404937473fb5272f115b65ce
Merged-In: I70acd4ce48853be728be1fb80b4b885d00a059a9
diff --git a/src/com/android/launcher3/model/FirstScreenBroadcast.java b/src/com/android/launcher3/model/FirstScreenBroadcast.java
index b8dbd08..4d017bd 100644
--- a/src/com/android/launcher3/model/FirstScreenBroadcast.java
+++ b/src/com/android/launcher3/model/FirstScreenBroadcast.java
@@ -17,12 +17,6 @@
 
 import static android.app.PendingIntent.FLAG_IMMUTABLE;
 import static android.app.PendingIntent.FLAG_ONE_SHOT;
-import static android.os.Process.myUserHandle;
-
-import static com.android.launcher3.pm.InstallSessionHelper.getUserHandle;
-
-import static java.util.stream.Collectors.groupingBy;
-import static java.util.stream.Collectors.mapping;
 
 import android.app.PendingIntent;
 import android.content.Context;