Fix multiple runs of bubbles persister test

Bug: 239892577
Test: Run WMShellUnitTests from sysui studio
Change-Id: I32580921641d95f67440000a6679d7899bbd36d3

libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/bubbles/storage/BubblePersistentRepositoryTest.kt

@@ -25,6 +25,7 @@ import com.android.wm.shell.bubbles.storage.BubbleXmlHelperTest.Companion.sparse
 import junit.framework.Assert.assertEquals
 import junit.framework.Assert.assertNotNull
 import junit.framework.Assert.assertTrue
+import org.junit.After
 import org.junit.Before
 import org.junit.Test
 import org.junit.runner.RunWith
@@ -61,6 +62,12 @@ class BubblePersistentRepositoryTest : ShellTestCase() {
         bubbles.put(1, user1Bubbles)
     }
 
+    @After
+    fun teardown() {
+        // Clean up the any persisted bubbles for the next run
+        repository.persistsToDisk(SparseArray())
+    }
+
     @Test
     fun testReadWriteOperation() {
         // Verify read before write doesn't cause FileNotFoundException
@@ -71,4 +78,4 @@ class BubblePersistentRepositoryTest : ShellTestCase() {
         repository.persistsToDisk(bubbles)
         assertTrue(sparseArraysEqual(bubbles, repository.readFromDisk()))
     }
-}
+}