Debug integrated terminal support doesn't get default terminal

[Tyriar]

This is now null by default

vscode/src/vs/workbench/contrib/debug/node/terminals.ts

Line 69 in b51019b

const shell_config = config.integrated.shell;

, so the debugger will be often falling back to the system shell instead of the terminal's actual default.

You can call into ITerminalInstanceService.getDefaultShellAndArgs (or getDefaultShell in terminalEnvironment.ts) to get a string now so you don't need to fallback to getSystemShell.

[Tyriar]

Verified by making sure variable resolution worked when debugging in integrated terminal "terminal.integrated.shell.linux": "${env:SHELL}"