Fix: use environment variable for keystore to prevent corruption

.github/workflows/release.yml

@@ -22,7 +22,9 @@ jobs:
         run: chmod +x gradlew
 
       - name: Create Keystore
-        run: echo "${{ secrets.RELEASE_KEYSTORE_BASE64 }}" | tr -d '\n ' | base64 --decode > app/release-key.jks
+        env:
+          KEYSTORE_B64: ${{ secrets.RELEASE_KEYSTORE_BASE64 }}
+        run: echo "$KEYSTORE_B64" | base64 -d > app/release-key.jks
 
       - name: Build Release APK
         env: