Demote failing pip tests

Stabilize presubmit

Test: atest WMShellFlickerTests
Change-Id: If98bc91eabc81006dfb9d4a82a693c0e61b39b60

libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/pip/EnterPipOnUserLeaveHintTest.kt

@@ -106,6 +106,11 @@ class EnterPipOnUserLeaveHintTest(testSpec: FlickerTestParameter) : EnterPipTest
         super.focusChanges()
     }
 
+    /** {@inheritDoc}  */
+    @Postsubmit
+    @Test
+    override fun pipAppWindowAlwaysVisible() = super.pipAppWindowAlwaysVisible()
+
     @Presubmit
     @Test
     override fun entireScreenCovered() {

libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/pip/EnterPipTest.kt

@@ -79,7 +79,7 @@ open class EnterPipTest(testSpec: FlickerTestParameter) : PipTransition(testSpec
      */
     @Presubmit
     @Test
-    fun pipAppWindowAlwaysVisible() {
+    open fun pipAppWindowAlwaysVisible() {
         testSpec.assertWm {
             this.isAppWindowVisible(pipApp)
         }

libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/pip/ExitPipViaExpandButtonClickTest.kt

@@ -84,6 +84,11 @@ class ExitPipViaExpandButtonClickTest(
     @Test
     override fun entireScreenCovered() = super.entireScreenCovered()
 
+    /** {@inheritDoc}  */
+    @FlakyTest(bugId = 197726610)
+    @Test
+    override fun pipLayerExpands() = super.pipLayerExpands()
+
     companion object {
         /**
          * Creates the test configurations.