Optimize Slider value animation

The previous implementation has read animated value during the
composition which lead to an increased memory usage and is against the
Compose guidelines. Now the slider only animates the value when the user
doesn't drag it and doesnt read animated value during the composition.

Flag: com.android.systemui.volume_redesign
Fixes: 405666272
Test: manual on foldable. Adjust volume using physical buttons and the
slider

Change-Id: I2c8506c483264cc01009d562c11c8c279c0b8289