Change marker to load_persist_props_action

load_persists_props_action is guaranteed to be triggered after /data is
mounted and adb is run. Changing the marker to fix flaky postsubmit.

Bug: 191153896
Test: atest
Change-Id: I4b4c732b1c5ae334e67486b73eb5143dc31af7de

tests/hostside/java/android/virt/test/MicrodroidTestCase.java

@@ -263,9 +263,7 @@ public class MicrodroidTestCase extends BaseHostJUnit4Test {
     }
 
     private void waitForMicrodroidBoot(long timeoutMinutes) throws Exception {
-        // Wait for a specific log from logd
-        // TODO(jiyong): use a more reasonable marker
-        final String pattern = "logd.auditd: start";
+        final String pattern = "load_persist_props_action";
         getDevice()
                 .executeShellV2Command(
                         "logcat --regex=\"" + pattern + "\" -m 1",