validate_secrets.yml: Update fastlane signal phrase that identifies bad MATCH_PASSWORD

Author: billybooth

.github/workflows/validate_secrets.yml

@@ -172,7 +172,7 @@ jobs:
             failed=true
             echo "::error::The FASTLANE_KEY secret is set but invalid. Verify that you copied it correctly from the API Key file (*.p8) you downloaded and try again."
           elif ! bundle exec fastlane validate_secrets 2>&1 | tee fastlane.log; then
-            if grep -q "bad decrypt" fastlane.log; then
+            if grep -q "Couldn't decrypt the repo" fastlane.log; then
               failed=true
               echo "::error::Unable to decrypt the Match-Secrets repository using the MATCH_PASSWORD secret. Verify that it is set correctly and try again."
             elif grep -q -e "required agreement" -e "license agreement" fastlane.log; then