[Motion][Split shade] Fix left side of split shade sometimes not overscrolling

The issue was caused by the split shade overscroll classes sometimes having
a reference to an old instance of QSFragment. To fix it, we now make sure
that it always uses the latest.

+ Drive by addition of making changed classes dumpable

Test: Manually. Wasn't able reproduce the issue anymore
Test: `adb shell dumpsys activity service SystemUI` to test the output of the new dumpables
Test: ShadeTransitionControllerTest.kt
Test: SplitShadeOverScrollerTest.kt
Test: SplitShadeLockScreenOverScrollerTest.kt
Fixes: 236221279
Change-Id: Ic8af4215efd1333f142f0197b76db88e2e57ead4