[SysUI][Floaty] Use pixel display size ratio for scaling rounded corners

Bug: 407953099
Flag: com.android.systemui.shared.enable_lpp_assist_invocation_effect
Test: manual, by following steps:
1. Get dump state of ScreenDecorations by "adb shell dumpsys activity
   service com.android.systemui | grep -i -A 100 "ScreenDecorations
   state""
2. Log the pixel display size ratio and scaled size of rounded corners for SqueezeEffect
3. Values obtained in #1 and #2 should match
4. Try the squeeze effect with scaled rounded corners on Pixel 8 Pro and Pixel 9. In both phones, rounded corners should smoothly transition from actual device rounded corners.
Change-Id: I1c84143a394607f4b574a61b67ca5379489c133e