Bug 1807289 - Disable failing customTabDownloadTest UI test

(cherry picked from commit 643680a1c6d543b79a50dc9d385c44bccdcfccc0)

app/src/androidTest/java/org/mozilla/fenix/ui/CustomTabsTest.kt

@@ -9,6 +9,7 @@ import androidx.test.uiautomator.UiDevice
 import okhttp3.mockwebserver.MockWebServer
 import org.junit.After
 import org.junit.Before
+import org.junit.Ignore
 import org.junit.Rule
 import org.junit.Test
 import org.mozilla.fenix.IntentReceiverActivity
@@ -174,6 +175,7 @@ class CustomTabsTest {
         }
     }
 
+    @Ignore("Failing, see: https://bugzilla.mozilla.org/show_bug.cgi?id=1807289")
     @SmokeTest
     @Test
     fun customTabDownloadTest() {