Improving diagnostics from fallback recents tests when phone is not unlocked

Failing earlier so that we don't get strange messages from the middle of the test.

Bug: 187761685
Test: presubmit
Flag: N/A
Change-Id: I1e3c70623e6f907bcc6bd0486b6c75afecb610e3

tests/src/com/android/launcher3/ui/AbstractLauncherUiTest.java

@@ -275,7 +275,8 @@ public abstract class AbstractLauncherUiTest {
         }
     }
 
-    private static void verifyKeyguardInvisible() {
+    /** Fail if lock screen is present */
+    public static void verifyKeyguardInvisible() {
         final boolean keyguardAlreadyVisible = sSeenKeyguard;
 
         sSeenKeyguard = sSeenKeyguard