Do not reset time if time was already set before

Test: Open many apps, ensure logs are correct
Test: ActivityMetricsLoggerTests
Fixes: 131603820
Change-Id: Icbd784db39ba083d1cd52beee88e128dec3ececa
diff --git a/services/core/java/com/android/server/wm/ActivityMetricsLogger.java b/services/core/java/com/android/server/wm/ActivityMetricsLogger.java
index 9decb58..feef5e2 100644
--- a/services/core/java/com/android/server/wm/ActivityMetricsLogger.java
+++ b/services/core/java/com/android/server/wm/ActivityMetricsLogger.java
@@ -326,7 +326,7 @@
                                       intent));
         }
 
-        if (!isAnyTransitionActive()) {
+        if (mCurrentTransitionStartTime == INVALID_START_TIME) {
 
             mCurrentTransitionStartTime = SystemClock.uptimeMillis();
             mLastTransitionStartTime = mCurrentTransitionStartTime;