WallpaperColors caching and synchronization

Making sure that colors are being cached in
WallpaperManagerService and that sysui won't
force a new color extraction.

Fixes: 62958267
Test: manual, reboot, look at systrace
Test: runtest -x cts/tests/app/src/android/app/cts/WallpaperManagerTest.java
Change-Id: Ic079a8e3d4d4ad65947b718dcc544f795c16f152
diff --git a/packages/SystemUI/src/com/android/systemui/Dependency.java b/packages/SystemUI/src/com/android/systemui/Dependency.java
index bb44123..776d076 100644
--- a/packages/SystemUI/src/com/android/systemui/Dependency.java
+++ b/packages/SystemUI/src/com/android/systemui/Dependency.java
@@ -268,6 +268,9 @@
         mProviders.put(AccessibilityManagerWrapper.class,
                 () -> new AccessibilityManagerWrapper(mContext));
 
+        // Creating a new instance will trigger color extraction.
+        // Thankfully this only happens once - during boot - and WallpaperManagerService
+        // loads colors from cache.
         mProviders.put(SysuiColorExtractor.class, () -> new SysuiColorExtractor(mContext));
 
         mProviders.put(TunablePaddingService.class, () -> new TunablePaddingService());