Two phases to set the password for disk encryption

Revert "Revert "Two phases to set the password for disk encryption""

This reverts commit a1eb750e75ff7c7ef7698deed4442449c33334c8.

Bug: 28154455
Bug: 28694324
Change-Id: I8106bfba28da401b9fd38349c6a9fa9a24f54712
diff --git a/services/core/java/com/android/server/LockSettingsStorage.java b/services/core/java/com/android/server/LockSettingsStorage.java
index 9ab6300..ab91a73 100644
--- a/services/core/java/com/android/server/LockSettingsStorage.java
+++ b/services/core/java/com/android/server/LockSettingsStorage.java
@@ -74,7 +74,7 @@
 
     private SparseArray<Integer> mStoredCredentialType;
 
-    class CredentialHash {
+    static class CredentialHash {
         static final int TYPE_NONE = -1;
         static final int TYPE_PATTERN = 1;
         static final int TYPE_PASSWORD = 2;