New API w/ multiple prefixes

Use the new API that contains multiple hash prefixes and a mask. Also
do some small refactoring necessary to handle multiple prefixes and
use a common implementation of the hash generation

Change-Id: Ib52f767ea6aadc30c67c5bdee949e9f9c5f04e44
diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index 43eb751..88cf138 100755
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -8583,6 +8583,24 @@
                 "ephemeral_cookie_max_size_bytes";
 
         /**
+         * A mask applied to the ephemeral hash to generate the hash prefix.
+         * <p>
+         * Type: int
+         *
+         * @hide
+         */
+        public static final String EPHEMERAL_HASH_PREFIX_MASK = "ephemeral_hash_prefix_mask";
+
+        /**
+         * Number of hash prefixes to send during ephemeral resolution.
+         * <p>
+         * Type: int
+         *
+         * @hide
+         */
+        public static final String EPHEMERAL_HASH_PREFIX_COUNT = "ephemeral_hash_prefix_count";
+
+        /**
          * The duration for caching uninstalled ephemeral apps.
          * <p>
          * Type: long