Consolodate Base64 Classes

both org.thoughtcrime.redphone.util and
org.thoughtcrime.securesms.util have a Base64 util class,
however, other than whitespace changes, and the securesms
one having a couple of extra methods, they are the same.

This commit removes org.thoughtcrime.redphone.util.Base64 and
anything referencing it now uses
org.thoughtcrime.securesms.util.Base64

Closes #4294

src/org/thoughtcrime/redphone/RedPhoneService.java

@@ -45,13 +45,13 @@ import org.thoughtcrime.redphone.signaling.SessionDescriptor;
 import org.thoughtcrime.redphone.signaling.SignalingException;
 import org.thoughtcrime.redphone.signaling.SignalingSocket;
 import org.thoughtcrime.redphone.ui.NotificationBarManager;
-import org.thoughtcrime.redphone.util.Base64;
 import org.thoughtcrime.redphone.util.UncaughtExceptionHandlerManager;
 import org.thoughtcrime.securesms.database.DatabaseFactory;
 import org.thoughtcrime.securesms.notifications.MessageNotifier;
 import org.thoughtcrime.securesms.recipients.Recipient;
 import org.thoughtcrime.securesms.recipients.RecipientFactory;
 import org.thoughtcrime.securesms.service.KeyCachingService;
+import org.thoughtcrime.securesms.util.Base64;
 import org.thoughtcrime.securesms.util.TextSecurePreferences;
 
 import java.io.IOException;

src/org/thoughtcrime/redphone/crypto/EncryptedSignalMessage.java

@@ -17,9 +17,7 @@
 
 package org.thoughtcrime.redphone.crypto;
 
-import android.content.Context;
+import org.thoughtcrime.securesms.util.Base64;
-
-import org.thoughtcrime.redphone.util.Base64;
 
 import java.io.IOException;
 import java.security.InvalidAlgorithmParameterException;

src/org/thoughtcrime/redphone/crypto/Otp.java

@@ -17,7 +17,7 @@
 
 package org.thoughtcrime.redphone.crypto;
 
-import org.thoughtcrime.redphone.util.Base64;
+import org.thoughtcrime.securesms.util.Base64;
 
 import java.security.InvalidKeyException;
 import java.security.NoSuchAlgorithmException;

src/org/thoughtcrime/redphone/signaling/signals/Signal.java

@@ -18,7 +18,7 @@
 package org.thoughtcrime.redphone.signaling.signals;
 
 import org.thoughtcrime.redphone.crypto.Otp;
-import org.thoughtcrime.redphone.util.Base64;
+import org.thoughtcrime.securesms.util.Base64;
 
 /**
  * Base class for constructing a signal.

src/org/thoughtcrime/securesms/mms/OutgoingGroupMediaMessage.java

@@ -3,10 +3,10 @@ package org.thoughtcrime.securesms.mms;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 
-import org.thoughtcrime.redphone.util.Base64;
 import org.thoughtcrime.securesms.attachments.Attachment;
 import org.thoughtcrime.securesms.database.ThreadDatabase;
 import org.thoughtcrime.securesms.recipients.Recipients;
+import org.thoughtcrime.securesms.util.Base64;
 import org.whispersystems.textsecure.internal.push.TextSecureProtos.GroupContext;
 
 import java.io.IOException;