Add RetryTestRule to FileDisplayActivityIT

showShares is flaky

Signed-off-by: Álvaro Brey <alvaro.brey@nextcloud.com>

app/src/androidTest/java/com/nextcloud/client/FileDisplayActivityIT.kt

@@ -50,6 +50,9 @@ class FileDisplayActivityIT : AbstractOnServerIT() {
         false
     )
 
+    @get:Rule
+    val retryRule = RetryTestRule() // showShares is flaky
+
     // @ScreenshotTest // todo run without real server
     @Test
     fun showShares() {