Add title for the mute section in conversation settings view.

Signal/src/ViewControllers/OWSConversationSettingsViewController.m

@@ -478,6 +478,9 @@ NS_ASSUME_NONNULL_BEGIN
     // Mute thread section.
 
     OWSTableSection *muteSection = [OWSTableSection new];
+    // We need a section header to separate the mute UI from the group settings UI.
+    muteSection.headerTitle = NSLocalizedString(
+        @"CONVERSATION_SETTINGS_MUTE_SECTION", @"Title for the 'mute' section of the conversation settings view.");
     [muteSection addItem:[OWSTableItem itemWithCustomCellBlock:^{
         UITableViewCell *cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:nil];
         OWSConversationSettingsViewController *strongSelf = weakSelf;

Signal/translations/en.lproj/Localizable.strings

@@ -433,6 +433,9 @@
 /* Label for button to mute a thread for a year. */
 "CONVERSATION_SETTINGS_MUTE_ONE_YEAR_ACTION" = "Mute for one year";
 
+/* Title for the 'mute' section of the conversation settings view. */
+"CONVERSATION_SETTINGS_MUTE_SECTION" = "Mute";
+
 /* Indicates that this thread is muted until a given date or time. Embeds {{The date or time which the thread is muted until}}. */
 "CONVERSATION_SETTINGS_MUTED_UNTIL_FORMAT" = "until %@";