Set a build remark

Pipeline remarks variable: BK_CI_BUILD_REMARK, with a short text to distinguish each build content, for example, set 'BK_CI_BUILD_REMARK' to the version number, to indicate the version of the package; Or set platform (windows/pc/ios/Android) to indicate the platform of the package **Application scenario:**Differentiate pipeline construction history

1. Set the remarks variable
2. Display note variables Note: Note variables are displayed only when the pipeline is finished