[FRP] Add illustration to lock screen setup

Added the illustration JPG files, and added
SetupWizardUtils.setIllustration method that will change the
illustrations in the layout.

Bug: 18482708
Change-Id: I8c6758113f07cd33f85eaf6bc019e8194d9a17ce

src/com/android/settings/SetupEncryptionInterstitial.java

@@ -96,6 +96,8 @@ public class SetupEncryptionInterstitial extends EncryptionInterstitial
         @Override
         public void onViewCreated(View view, Bundle savedInstanceState) {
             super.onViewCreated(view, savedInstanceState);
+            SetupWizardUtils.setIllustration(getActivity(),
+                    R.drawable.setup_illustration_lock_screen);
             SetupWizardUtils.setHeaderText(getActivity(), R.string.encryption_interstitial_header);
         }
     }