Fix: Ensure slider value is reset to min when disabled

If the slider's disabled state doesn't change from the previous state, the value may not be correctly updated to its minimum. This change removes the redundant check, guaranteeing the value is always reset when the slider is disabled, regardless of its prior state.

Flag: EXEMPT bugfix
Bug: 417628947
Test: atest AmbientVolumeLayoutTest
Change-Id: I91f55968183c13d94c83bbcdc7440adcd6fcd4e6