Increase polling timeout to 20 seconds.

Sometimes we don't get MEDIA_MOUNTED state for ExternalStorageState in
10 seconds. Instead of failing the test, we can wait for few more
seconds.

Bug: 158964245
Test: atest CtsScopedStoragePublicVolumeHostTest
Change-Id: I3edcd592419e46017740958d9a0fd63b935e1a14
Merged-In: I3edcd592419e46017740958d9a0fd63b935e1a14
(cherry picked from commit 78dc06a4a688a01308c369418156e2f7cff78e40)
diff --git a/hostsidetests/scopedstorage/libs/ScopedStorageTestLib/src/android/scopedstorage/cts/lib/TestUtils.java b/hostsidetests/scopedstorage/libs/ScopedStorageTestLib/src/android/scopedstorage/cts/lib/TestUtils.java
index 70b6d90..d43500a 100644
--- a/hostsidetests/scopedstorage/libs/ScopedStorageTestLib/src/android/scopedstorage/cts/lib/TestUtils.java
+++ b/hostsidetests/scopedstorage/libs/ScopedStorageTestLib/src/android/scopedstorage/cts/lib/TestUtils.java
@@ -107,7 +107,7 @@
     private static File sExternalStorageDirectory = Environment.getExternalStorageDirectory();
     private static String sStorageVolumeName = MediaStore.VOLUME_EXTERNAL;
 
-    private static final long POLLING_TIMEOUT_MILLIS = TimeUnit.SECONDS.toMillis(10);
+    private static final long POLLING_TIMEOUT_MILLIS = TimeUnit.SECONDS.toMillis(20);
     private static final long POLLING_SLEEP_MILLIS = 100;
 
     /**