- Added Sign_KeyPassword setting for private key password
- Updated Signapk.cs to use separate keystore and key passwords
- Added textBox4 and label23 for Private key password field in UI
- Fixed password verification issue when signing APKs with keystore
Previously, the same password was used for both keystore and key access,
causing 'Password verification failed' errors when they were different.
This update allows users to specify different passwords for keystore
and private key, resolving java.security.UnrecoverableKeyException.
