Call Activity.onTrimMemory() to ensure render thread cache is also trimmed

Bug: 76162466
Change-Id: Ie3cf9076ba8149c0f2d7e58b5ca0c974ae914c18
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index 1285a2b..2c08169 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -738,7 +738,7 @@
         getStateManager().moveToRestState();
 
         // Workaround for b/78520668, explicitly trim memory once UI is hidden
-        UiFactory.onTrimMemory(this, TRIM_MEMORY_UI_HIDDEN);
+        onTrimMemory(TRIM_MEMORY_UI_HIDDEN);
     }
 
     @Override