Add a unit test to test hiding IME when dismissing biometrics UI

For verifying CL[1] fixed IME flicker issue during biometrics UI
dismissed by focus-lost.

[1]: I541f41832753ea1f4f48f6c4745649606b37d207

Bug: 247705580
Test: atest AuthContainerViewTest#t\
        estDismissesOnFocusLoss_hidesKeyboardWhenVisible
Change-Id: I7622a30778677ed712bbe46d3ea30a0ddb89dfbb

packages/SystemUI/tests/src/com/android/systemui/biometrics/AuthContainerViewTest.kt

@@ -35,6 +35,8 @@ import android.view.WindowInsets
 import android.view.WindowManager
 import android.widget.ScrollView
 import androidx.test.filters.SmallTest
+import com.android.dx.mockito.inline.extended.ExtendedMockito.doReturn
+import com.android.dx.mockito.inline.extended.ExtendedMockito.spyOn
 import com.android.internal.jank.InteractionJankMonitor
 import com.android.internal.widget.LockPatternUtils
 import com.android.systemui.R
@@ -142,6 +144,35 @@ class AuthContainerViewTest : SysuiTestCase() {
         assertThat(container.parent).isNull()
     }
 
+    @Test
+    fun testDismissesOnFocusLoss_hidesKeyboardWhenVisible() {
+        val container = initializeFingerprintContainer(
+            authenticators = BiometricManager.Authenticators.DEVICE_CREDENTIAL
+        )
+        waitForIdleSync()
+
+        val requestID = authContainer?.requestId ?: 0L
+
+        // Simulate keyboard was shown on the credential view
+        val windowInsetsController = container.windowInsetsController
+        spyOn(windowInsetsController)
+        spyOn(container.rootWindowInsets)
+        doReturn(true).`when`(container.rootWindowInsets).isVisible(WindowInsets.Type.ime())
+
+        container.onWindowFocusChanged(false)
+        waitForIdleSync()
+
+        // Expect hiding IME request will be invoked when dismissing the view
+        verify(windowInsetsController)?.hide(WindowInsets.Type.ime())
+
+        verify(callback).onDismissed(
+            eq(AuthDialogCallback.DISMISSED_USER_CANCELED),
+            eq<ByteArray?>(null), /* credentialAttestation */
+            eq(requestID)
+        )
+        assertThat(container.parent).isNull()
+    }
+
     @Test
     fun testActionAuthenticated_sendsDismissedAuthenticated() {
         val container = initializeFingerprintContainer()