Translate bool->string explicitly when they don't match

This is necessary since implicit conversions cast to int, true->1, false->0 instead of to
string: true->"true", false->"false". The latter is what Terraform providers expect.

pkg/tfbridge/schema.go

@@ -365,6 +365,12 @@ func (ctx *conversionContext) MakeTerraformInput(name string, old, v resource.Pr
 	case v.IsNull():
 		return nil, nil
 	case v.IsBool():
+		if tfs != nil && tfs.Type() == shim.TypeString {
+			if v.BoolValue() {
+				return "true", nil
+			}
+			return "false", nil
+		}
 		return v.BoolValue(), nil
 	case v.IsNumber():
 		if tfs != nil && tfs.Type() == shim.TypeFloat {