Populate WaitResult with AML data for hot launches

Make the time of "am start -W" and metrics log are consistent.

Bug: 120981435
Bug: 123355661
Test: atest ActivityMetricsLoggerTests# \
            testAppHotLaunchSetsWaitResultDelayData

Change-Id: I83a249146763e866048f7c4f92ec584b5fb4e4f0
diff --git a/services/core/java/com/android/server/wm/ActivityMetricsLogger.java b/services/core/java/com/android/server/wm/ActivityMetricsLogger.java
index f9b6bba..ff2c671 100644
--- a/services/core/java/com/android/server/wm/ActivityMetricsLogger.java
+++ b/services/core/java/com/android/server/wm/ActivityMetricsLogger.java
@@ -823,7 +823,14 @@
             return StatsLog.APP_START_OCCURRED__TYPE__HOT;
         }
         return StatsLog.APP_START_OCCURRED__TYPE__UNKNOWN;
-     }
+    }
+
+    /** @return the last known window drawn delay of the given windowing mode. */
+    int getLastDrawnDelayMs(@WindowingMode int windowingMode) {
+        final WindowingModeTransitionInfo info = mLastWindowingModeTransitionInfo.get(
+                windowingMode);
+        return info != null ? info.windowsDrawnDelayMs : INVALID_DELAY;
+    }
 
     WindowingModeTransitionInfoSnapshot logAppTransitionReportedDrawn(ActivityRecord r,
             boolean restoredFromBundle) {