Resolve kokoro build failure for CocoaPods builds. (#9306)
Resolve kokoro build failure for CocoaPods builds. (#9306)

this PR uninstalls the rubygems-bundler which is not needed anymore and causing build failures. See more details in tracking bug https://github.com/material-components/material-components-ios/issues/9305
material-components/material-components-ios,material-components/material-components-ios,material-components/material-components-ios,material-components/material-components-ios,material-components/material-components-ios