Show Gmail app delete button for Gmail/OAuth

app/src/main/java/eu/faircode/email/FragmentDialogAccount.java

@@ -21,6 +21,7 @@ package eu.faircode.email;
 
 import static android.app.Activity.RESULT_OK;
 import static eu.faircode.email.ServiceAuthenticator.AUTH_TYPE_GMAIL;
+import static eu.faircode.email.ServiceAuthenticator.AUTH_TYPE_OAUTH;
 
 import android.app.Dialog;
 import android.content.Context;
@@ -166,9 +167,9 @@ public class FragmentDialogAccount extends FragmentDialogBase {
             public void onChanged(EntityAccount account) {
                 tvName.setText(account.name);
                 ibEditName.setEnabled(true);
-                btnGmail.setVisibility(
-                        hasGmail && account.auth_type == AUTH_TYPE_GMAIL
-                                ? View.VISIBLE : View.GONE);
+                boolean isGmail = (account.auth_type == AUTH_TYPE_GMAIL ||
+                        (account.auth_type == AUTH_TYPE_OAUTH && "gmail".equals(account.provider)));
+                btnGmail.setVisibility(hasGmail && isGmail ? View.VISIBLE : View.GONE);
             }
         });