Fix ripple opacity to match the previous config.

the default opacity was 0.45 in the shader. the color utilities class
that we use expects the alpha value in the range of 0-255, thus 0.45
should be mapped to 255*0.4=114.75 (which is roughly 115).
please find the recordings in the bug linked!

Bug: 259187018
Test: manual
Change-Id: I355da98c3397cd760899b82442e7a07012b8b7f7