Disallow disable / hide device provision app

+ Rename functions in ProtectedPackages.
+ Add a Set in ProtectedPackages to store protected package.

Bug: 29116229
Change-Id: Ib7dd93a158c09ebbf70f4d57c1afbd2c5102edbd
diff --git a/core/java/android/content/pm/PackageManagerInternal.java b/core/java/android/content/pm/PackageManagerInternal.java
index 14f7727..d208fe7 100644
--- a/core/java/android/content/pm/PackageManagerInternal.java
+++ b/core/java/android/content/pm/PackageManagerInternal.java
@@ -157,7 +157,7 @@
             int deviceOwnerUserId, String deviceOwner, SparseArray<String> profileOwners);
 
     /**
-     * Whether a package's data be cleared.
+     * Returns {@code true} if a given package can't be wiped. Otherwise, returns {@code false}.
      */
-    public abstract boolean canPackageBeWiped(int userId, String packageName);
+    public abstract boolean isPackageDataProtected(int userId, String packageName);
 }