Fix lock icons & l18n

Signed-off-by: Henrik Storch <henrik.storch@nextcloud.com>

iOSClient/Menu/NCMenuAction.swift

@@ -216,7 +216,7 @@ extension NCMenuAction {
     /// Lock or unlock a file using files_lock
     static func lockUnlockFiles(shouldLock: Bool, metadatas: [tableMetadata], completion: (() -> Void)? = nil) -> NCMenuAction {
         let titleKey = !shouldLock ? "_unlock_file_" : "_lock_file_"
-        let imageName = !shouldLock ? "_unlock_" : "_lock_"
+        let imageName = !shouldLock ? "lock.open" : "lock"
         return NCMenuAction(
             title: NSLocalizedString(titleKey, comment: ""),
             icon: NCUtility.shared.loadImage(named: imageName),

iOSClient/Supporting Files/en.lproj/Localizable.strings

@@ -147,6 +147,10 @@
 "_view_in_folder_"          = "View in folder";
 "_leave_share_"             = "Leave this share";
 
+/* Files lock */
+"_lock_"                    = "Lock";
+"_unlock_"                  = "Unock";
+
 /* Remove a file from a list, don't delete it entirely */
 "_remove_file_"             = "Remove file";