android: Throw an exception if UUID can't get parsed

The parser is quite picky and e.g. doesn't accept UUIDs without dashes.
Even without a specific error, this at least points the users into the
right direction.

Fixes #3583.

src/frontends/android/app/src/main/java/org/strongswan/android/ui/VpnProfileImportActivity.java

@@ -463,8 +463,7 @@ public class VpnProfileImportActivity extends AppCompatActivity
 		}
 		catch (IllegalArgumentException e)
 		{
-			e.printStackTrace();
-			return null;
+			throw new JSONException(getString(R.string.profile_import_failed_value, "uuid"));
 		}
 		ParsedVpnProfile profile = new ParsedVpnProfile();
 		Integer flags = 0;