Clean up visibility related flags in ActivityRecord

- Replace visible and hiddenRequested flag by a single flag
  mVisibleRequested.
- Merge setVisible() into setVisiblity().

Test: Refactoring, all existing tests pass.
Bug: 80414790
Change-Id: I7bafdb86e6b8431046775d3968d24f85c3fac45a
diff --git a/services/core/java/com/android/server/wm/ActivityMetricsLogger.java b/services/core/java/com/android/server/wm/ActivityMetricsLogger.java
index 73034b0..0a861ad 100644
--- a/services/core/java/com/android/server/wm/ActivityMetricsLogger.java
+++ b/services/core/java/com/android/server/wm/ActivityMetricsLogger.java
@@ -548,7 +548,7 @@
     private static boolean hasActivityToBeDrawn(Task t) {
         for (int i = t.getChildCount() - 1; i >= 0; --i) {
             final ActivityRecord r = t.getChildAt(i);
-            if (r.visible && !r.mDrawn && !r.finishing) {
+            if (r.mVisibleRequested && !r.mDrawn && !r.finishing) {
                 return true;
             }
         }