Fix monkey crash on selecting account sync prefernece.

When running monkey, the authority in the preference might not have been
properly set. Add a check for valid authority before trying to update
the sync automatically setting.

Change-Id: I59f910565fc9f128e86bd92337135fe46fed12e1
Fixes: 80551551
Test: make RunSettingsRoboTests

tests/robotests/src/com/android/settings/accounts/AccountSyncSettingsTest.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.settings.accounts;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.when;
+
+import android.accounts.Account;
+import android.app.Activity;
+import android.content.Context;
+import android.os.UserHandle;
+import com.android.settings.testutils.SettingsRobolectricTestRunner;
+import com.android.settings.testutils.shadow.ShadowContentResolver;
+import org.junit.After;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RuntimeEnvironment;
+import org.robolectric.annotation.Config;
+import org.robolectric.util.ReflectionHelpers;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(shadows = {ShadowContentResolver.class})
+public class AccountSyncSettingsTest {
+
+    @After
+    public void tearDown() {
+        ShadowContentResolver.reset();
+    }
+
+    @Test
+    public void onPreferenceTreeClick_nullAuthority_shouldNotCrash() {
+        final Context context = RuntimeEnvironment.application;
+        final AccountSyncSettings settings = spy(new AccountSyncSettings());
+        when(settings.getActivity()).thenReturn(mock(Activity.class));
+        final SyncStateSwitchPreference preference = new SyncStateSwitchPreference(context,
+                new Account("acct1", "type1"), "" /* authority */, "testPackage", 1 /* uid */);
+        preference.setOneTimeSyncMode(false);
+        ReflectionHelpers.setField(settings, "mUserHandle", UserHandle.CURRENT);
+
+        settings.onPreferenceTreeClick(preference);
+        // no crash
+    }
+}