make dropdown arrow larger to meet accessibility requirement (#127839)
make dropdown arrow larger to meet accessibility requirement (#127839)

* make dropdown arrow bold

* Update style.css
Microsoft/vscode,microsoft/vscode,Microsoft/vscode,Microsoft/vscode,eamodio/vscode,Microsoft/vscode,eamodio/vscode,Microsoft/vscode,Microsoft/vscode,eamodio/vscode,eamodio/vscode,Microsoft/vscode,microsoft/vscode,microsoft/vscode,eamodio/vscode,Microsoft/vscode,eamodio/vscode,eamodio/vscode,microsoft/vscode,eamodio/vscode,microsoft/vscode,microsoft/vscode,Microsoft/vscode,microsoft/vscode,microsoft/vscode,eamodio/vscode,Microsoft/vscode,eamodio/vscode,eamodio/vscode,Microsoft/vscode,eamodio/vscode,microsoft/vscode,eamodio/vscode,eamodio/vscode,microsoft/vscode,microsoft/vscode,microsoft/vscode,Microsoft/vscode,eamodio/vscode,Microsoft/vscode,eamodio/vscode,microsoft/vscode,microsoft/vscode,Microsoft/vscode,microsoft/vscode,eamodio/vscode,Microsoft/vscode,microsoft/vscode,Microsoft/vscode,microsoft/vscode,Microsoft/vscode