Fixed regression on jank test of changeBrightness

Replace using hardware layer for alpha animation with drawing
transparent color with MULTIPLY mode.

Test: atest google/perf/jank/SystemUI/UbSystemUIJankTests-Trace:android.platform.systemui.tests.jank.SystemUiJankTests#testChangeBrightness
Change-Id: I9615af89c4418dd90ccc86e9e7c71d88e7121826
Fixes: 79266233
5 files changed