Adding field to material input mixin so that user can specify the label color when there is an error and the label is focused.  Previously, the focus color was always being applied even when there was an error in the input.
Adding field to material input mixin so that user can specify the label color when there is an error and the label is focused.  Previously, the focus color was always being applied even when there was an error in the input.

PiperOrigin-RevId: 197491515

angulardart/angular_components,angulardart/angular_components,angulardart/angular_components