added enc key delete

app/src/main/java/ru/vtosters/lite/encryption/base/IMProcessor.java

@@ -5,7 +5,6 @@ import static ru.vtosters.lite.utils.Preferences.getBoolValue;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
-import ru.vtosters.lite.utils.AndroidUtils;
 import ru.vtosters.lite.utils.Preferences;
 
 public abstract class IMProcessor {
@@ -84,4 +83,8 @@ public abstract class IMProcessor {
     public String getEncryptionKeyFor(int id) {
         return Preferences.getPreferences().getString("VT_IMEncodeKey_" + getPrefKey() + "_" + id, null);
     }
+
+    public void removeEncryptionKeyFor(int id) {
+        Preferences.getPreferences().edit().remove("VT_IMEncodeKey_" + getPrefKey() + "_" + id).apply();
+    }
 }

app/src/main/java/ru/vtosters/lite/hooks/CryptImHook.java

@@ -100,7 +100,7 @@ public class CryptImHook {
             key = enabled.getEncryptionKeyFor(peerId);
         }
 
-        if (key.equals("VTAesDefault")) {
+        if (Objects.equals(key, "VTAesDefault")) {
             key = null;
         }
 
@@ -128,6 +128,9 @@ public class CryptImHook {
                     Editable edit = editText.getText();
                     finalEnabled.setEncryptionKeyFor(peerId, edit == null ? null : edit.toString());
                 }).setNegativeButton(android.R.string.cancel, null)
+                .setNeutralButton("Удалить ключ", (dialog, which) -> {
+                    finalEnabled.removeEncryptionKeyFor(peerId);
+                })
                 .show();
     }
 }