Wire default resource modifier through install path and builder

Add --default-resource-modifier-configmap to the install CLI and
deployment builder so administrators can configure it during velero
install. Wire through VeleroOptions and podTemplateConfig following
the existing --backup-repository-configmap pattern.

Add SkipDefaultResourceModifier builder method to RestoreBuilder.

Signed-off-by: Shubham Pampattiwar <spampatt@redhat.com>

pkg/builder/restore_builder.go

@@ -181,3 +181,9 @@ func (b *RestoreBuilder) ResourcePoliciesConfigmap(name string) *RestoreBuilder
 	}
 	return b
 }
+
+// SkipDefaultResourceModifier sets whether to skip the server default resource modifier.
+func (b *RestoreBuilder) SkipDefaultResourceModifier(val bool) *RestoreBuilder {
+	b.object.Spec.SkipDefaultResourceModifier = &val
+	return b
+}