Not generating memory dump for intentional leak tests

Memory dump can be generated only once, so generating it in the intentional leak test leaves us without a meaningful dump if a real leak happens later, and produces a confusing message that the dump was already generated.

Bug: 195319692
Test: presubmit
Change-Id: I35932deba0c46ddb27362467109daf74d75cbff4
diff --git a/tests/src/com/android/launcher3/ui/AbstractLauncherUiTest.java b/tests/src/com/android/launcher3/ui/AbstractLauncherUiTest.java
index 075505e..3e98983 100644
--- a/tests/src/com/android/launcher3/ui/AbstractLauncherUiTest.java
+++ b/tests/src/com/android/launcher3/ui/AbstractLauncherUiTest.java
@@ -126,10 +126,12 @@
     private static String getActivityLeakErrorMessage(LauncherInstrumentation launcher) {
         sActivityLeakReported = true;
         return "Activity leak detector has found leaked activities, "
-                + dumpHprofData(launcher) + ".";
+                + dumpHprofData(launcher, false) + ".";
     }
 
-    public static String dumpHprofData(LauncherInstrumentation launcher) {
+    public static String dumpHprofData(LauncherInstrumentation launcher, boolean intentionalLeak) {
+        if (intentionalLeak) return "intentional leak; not generating dump";
+
         String result;
         if (sDumpWasGenerated) {
             Log.d("b/195319692", "dump has already been generated by another test",