Fix flakey shortcut CTS

- After changing the default launcher, clear the cached launcher.

Bug: 72753182
Test: atest CtsShortcutManagerTestCases
Test: atest CtsShortcutHostTestCases
Change-Id: If9b2e0fecb4c94320e5e6125f61c5802bebeb292
diff --git a/services/tests/shortcutmanagerutils/src/com/android/server/pm/shortcutmanagertest/ShortcutManagerTestUtils.java b/services/tests/shortcutmanagerutils/src/com/android/server/pm/shortcutmanagertest/ShortcutManagerTestUtils.java
index 99eb846..e36586e 100644
--- a/services/tests/shortcutmanagerutils/src/com/android/server/pm/shortcutmanagertest/ShortcutManagerTestUtils.java
+++ b/services/tests/shortcutmanagerutils/src/com/android/server/pm/shortcutmanagertest/ShortcutManagerTestUtils.java
@@ -210,6 +210,9 @@
         runCommand(instrumentation, "cmd package set-home-activity --user "
                 + instrumentation.getContext().getUserId() + " " + component,
                 result -> result.contains("Success"));
+        runCommand(instrumentation, "cmd shortcut clear-default-launcher --user "
+                        + instrumentation.getContext().getUserId(),
+                result -> result.contains("Success"));
     }
 
     public static void setDefaultLauncher(Instrumentation instrumentation, Context packageContext) {