Clear up /data/misc_ce/user folder on delete and reboot

Clean up the folder to avoid leaving residue behind when
a user is removed. This was causing issues with reusing
the userid. Also check on reboot for incomplete cleanup
and remove the folders.

Change-Id: Icd21d2669249d5f87032ef0fe95bad49537fa477
Fixes: 34736064
Test: Manual
diff --git a/core/java/android/os/Environment.java b/core/java/android/os/Environment.java
index 8d9ceb6..7cdb3ce 100644
--- a/core/java/android/os/Environment.java
+++ b/core/java/android/os/Environment.java
@@ -272,6 +272,11 @@
     }
 
     /** {@hide} */
+    public static File getDataMiscCeDirectory() {
+        return buildPath(getDataDirectory(), "misc_ce");
+    }
+
+    /** {@hide} */
     public static File getDataMiscCeDirectory(int userId) {
         return buildPath(getDataDirectory(), "misc_ce", String.valueOf(userId));
     }