Replace generic ErrorFragment with specific one

when key agreement protocol doesn't match

briar-android/src/main/java/org/briarproject/briar/android/keyagreement/ContactExchangeErrorFragment.java

@@ -2,7 +2,6 @@ package org.briarproject.briar.android.keyagreement;
 
 import android.os.Bundle;
 import android.support.annotation.Nullable;
-import android.support.annotation.StringRes;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -29,10 +28,10 @@ public class ContactExchangeErrorFragment extends BaseFragment {
 			ContactExchangeErrorFragment.class.getName();
 	private static final String ERROR_MSG = "errorMessage";
 
-	public static ContactExchangeErrorFragment newInstance(@StringRes int res) {
+	public static ContactExchangeErrorFragment newInstance(String errorMsg) {
 		ContactExchangeErrorFragment f = new ContactExchangeErrorFragment();
 		Bundle args = new Bundle();
-		args.putInt(ERROR_MSG, res);
+		args.putString(ERROR_MSG, errorMsg);
 		f.setArguments(args);
 		return f;
 	}
@@ -60,7 +59,7 @@ public class ContactExchangeErrorFragment extends BaseFragment {
 		if (args == null) {
 			throw new IllegalArgumentException("Use newInstance()");
 		}
-		explanation.setText(args.getInt(ERROR_MSG));
+		explanation.setText(args.getString(ERROR_MSG));
 
 		// make feedback link clickable
 		TextView sendFeedback = v.findViewById(R.id.sendFeedback);

briar-android/src/main/java/org/briarproject/briar/android/keyagreement/KeyAgreementActivity.java

@@ -188,7 +188,8 @@ public abstract class KeyAgreementActivity extends BriarActivity implements
 	}
 
 	protected void showErrorFragment(@StringRes int errorResId) {
-		BaseFragment f = ContactExchangeErrorFragment.newInstance(errorResId);
+		String errorMsg = getString(errorResId);
+		BaseFragment f = ContactExchangeErrorFragment.newInstance(errorMsg);
 		showNextFragment(f);
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/keyagreement/KeyAgreementFragment.java

@@ -36,7 +36,6 @@ import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.fragment.BaseEventFragment;
-import org.briarproject.briar.android.fragment.ErrorFragment;
 import org.briarproject.briar.android.view.QrCodeView;
 
 import java.io.IOException;
@@ -247,7 +246,7 @@ public class KeyAgreementFragment extends BaseEventFragment
 			reset();
 			String msg = getString(R.string.qr_code_unsupported,
 					getString(R.string.app_name));
-			showNextFragment(ErrorFragment.newInstance(msg));
+			showNextFragment(ContactExchangeErrorFragment.newInstance(msg));
 		} catch (CameraException e) {
 			logCameraExceptionAndFinish(e);
 		} catch (IOException | IllegalArgumentException e) {