Omit TestStorageTest@writeInternalFile from running on multi user

PiperOrigin-RevId: 732969678

Author: brettchabot

services/storage/javatests/androidx/test/services/storage/TestStorageTest.java

@@ -19,8 +19,12 @@
 import static com.google.common.truth.Truth.assertThat;
 import static junit.framework.TestCase.fail;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assume.assumeTrue;
 
+import android.content.Context;
 import android.net.Uri;
+import android.os.Build;
+import android.os.UserManager;
 import androidx.test.services.storage.file.HostedFile;
 import androidx.test.services.storage.internal.TestStorageUtil;
 import java.io.BufferedReader;
@@ -110,11 +114,23 @@ public void addOutputProperties() throws Exception {
 
   @Test
   public void writeInternalFile() throws IOException {
+    // known not to work in multi-user mode
+    assumeTrue(isSystemUser());
     try (OutputStream output = testStorage.openInternalOutputFile("path/to/file")) {
       output.write(new byte[] {'h', 'e', 'l', 'l', 'o'});
     }
   }
 
+  private static boolean isSystemUser() {
+    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
+      return true;
+    } else {
+      UserManager um =
+          ((UserManager) getApplicationContext().getSystemService(Context.USER_SERVICE));
+      return um.isSystemUser();
+    }
+  }
+
   @Test
   public void readWriteOverwriteReadFile() throws IOException {
     try (OutputStream output = testStorage.openOutputFile("path/to/file")) {