iso: fix media ejection in text-based finishview (#72)

In text-based installation mode, removing the installation media in the
finishview causes boot-up errors due to incomplete processes.

This commit adds an eject operation in the finishview to complete pending
write operations and properly close the file system, allowing the user to
remove the installation media in finishview.

Signed-off-by: Mun Chun Yep <mun.chun.yep@intel.com>

Author: yepmunchun

toolkit/tools/imagegen/attendedinstaller/views/finishview/finishview.go

@@ -15,6 +15,7 @@ import (
 	"github.com/microsoft/azurelinux/toolkit/tools/imagegen/attendedinstaller/uiutils"
 	"github.com/microsoft/azurelinux/toolkit/tools/imagegen/configuration"
 	"github.com/microsoft/azurelinux/toolkit/tools/internal/logger"
+	"github.com/microsoft/azurelinux/toolkit/tools/internal/shell"
 )
 
 // UI constants.
@@ -136,6 +137,14 @@ func (fv *FinishView) OnShow() {
 	// since the installation time is not known during Initialize().
 	// Force a focus change as the flex box has just been initialized in updateTextSize().
 	fv.app.SetFocus(fv.centeredFlex)
+
+	const squashErrors = false
+	program := "eject"
+	commandArgs := []string{
+		"--cdrom",
+		"--force",
+	}
+	shell.ExecuteLive(squashErrors, program, commandArgs...)
 }
 
 func (fv *FinishView) updateTextSize() {