String improvement: Blocking and unblocking contacts

This fixes/improves several strings related to blocking and unblocking
contacts regarding:

- Wording consistency
- Compliance with Google's Design Guidelines
- Clarity

Closes #5696
// FREEBIE

res/values/strings.xml

@@ -142,8 +142,8 @@
     <string name="ConversationActivity_mms_not_supported_title">MMS not supported</string>
     <string name="ConversationActivity_mms_not_supported_message">This message cannot be sent since your carrier doesn\'t support MMS.</string>
     <string name="ConversationActivity_specify_recipient">Please choose a contact</string>
-    <string name="ConversationActivity_unblock_question">Unblock?</string>
-    <string name="ConversationActivity_are_you_sure_you_want_to_unblock_this_contact">Are you sure you want to unblock this contact?</string>
+    <string name="ConversationActivity_unblock_this_contact_question">Unblock this contact?</string>
+    <string name="ConversationActivity_you_will_once_again_be_able_to_receive_messages_and_calls_from_this_contact">You will once again be able to receive messages and calls from this contact.</string>
     <string name="ConversationActivity_unblock">Unblock</string>
     <string name="ConversationActivity_attachment_exceeds_size_limits">Attachment exceeds size limits for the type of message you\'re sending.</string>
     <string name="ConversationActivity_quick_camera_unavailable">Camera unavailable</string>
@@ -437,10 +437,10 @@
 
     <!-- RecipientPreferencesActivity -->
     <string name="RecipientPreferenceActivity_block_this_contact_question">Block this contact?</string>
-    <string name="RecipientPreferenceActivity_you_will_no_longer_receive_messages_or_calls_from_this_user">You will no longer receive messages or calls from this user.</string>
+    <string name="RecipientPreferenceActivity_you_will_no_longer_receive_messages_and_calls_from_this_contact">You will no longer receive messages and calls from this contact.</string>
     <string name="RecipientPreferenceActivity_block">Block</string>
     <string name="RecipientPreferenceActivity_unblock_this_contact_question">Unblock this contact?</string>
-    <string name="RecipientPreferenceActivity_are_you_sure_you_want_to_unblock_this_contact">Are you sure you want to unblock this contact?</string>
+    <string name="RecipientPreferenceActivity_you_will_once_again_be_able_to_receive_messages_and_calls_from_this_contact">You will once again be able to receive messages and calls from this contact.</string>
     <string name="RecipientPreferenceActivity_unblock">Unblock</string>
     <string name="RecipientPreferenceActivity_enabled">Enabled</string>
     <string name="RecipientPreferenceActivity_disabled">Disabled</string>

src/org/thoughtcrime/securesms/ConversationActivity.java

@@ -554,8 +554,8 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
 
   private void handleUnblock() {
     new AlertDialog.Builder(this)
-        .setTitle(R.string.ConversationActivity_unblock_question)
-        .setMessage(R.string.ConversationActivity_are_you_sure_you_want_to_unblock_this_contact)
+        .setTitle(R.string.ConversationActivity_unblock_this_contact_question)
+        .setMessage(R.string.ConversationActivity_you_will_once_again_be_able_to_receive_messages_and_calls_from_this_contact)
         .setNegativeButton(android.R.string.cancel, null)
         .setPositiveButton(R.string.ConversationActivity_unblock, new DialogInterface.OnClickListener() {
           @Override

src/org/thoughtcrime/securesms/RecipientPreferenceActivity.java

@@ -468,7 +468,7 @@ public class RecipientPreferenceActivity extends PassphraseRequiredActionBarActi
       private void handleBlock() {
         new AlertDialog.Builder(getActivity())
             .setTitle(R.string.RecipientPreferenceActivity_block_this_contact_question)
-            .setMessage(R.string.RecipientPreferenceActivity_you_will_no_longer_receive_messages_or_calls_from_this_user)
+            .setMessage(R.string.RecipientPreferenceActivity_you_will_no_longer_receive_messages_and_calls_from_this_contact)
             .setCancelable(true)
             .setNegativeButton(android.R.string.cancel, null)
             .setPositiveButton(R.string.RecipientPreferenceActivity_block, new DialogInterface.OnClickListener() {
@@ -482,7 +482,7 @@ public class RecipientPreferenceActivity extends PassphraseRequiredActionBarActi
       private void handleUnblock() {
         new AlertDialog.Builder(getActivity())
             .setTitle(R.string.RecipientPreferenceActivity_unblock_this_contact_question)
-            .setMessage(R.string.RecipientPreferenceActivity_are_you_sure_you_want_to_unblock_this_contact)
+            .setMessage(R.string.RecipientPreferenceActivity_you_will_once_again_be_able_to_receive_messages_and_calls_from_this_contact)
             .setCancelable(true)
             .setNegativeButton(android.R.string.cancel, null)
             .setPositiveButton(R.string.RecipientPreferenceActivity_unblock, new DialogInterface.OnClickListener() {