feat(color correction): Disable slider when not applicable

We received feedback that slider should be disabled when it's not
applicable, namely when it's off and when mode == gray scale.

Bug: 351920992
Test: Locally tested + unit tests
Flag: com.android.server.accessibility.enable_color_correction_saturation

Change-Id: I1162a501a797a1d2b30da76f0c75e5fdea3f61d2