Initialize the volume seekbar preference max and progress.

When the media stream is set, initialize the preference max and progress
with the streams current value. Otherwise, when we initialize the seekbar
volumizer, it will first set the seekbar max to 0 and progress to 0,
then update with the correct value, which will result in the jank that
is seen when the sound settings are displayed.

Change-Id: I515c97bbc6ec38bbe92755e3d7cb53bb13ac52d0
Fix: 34035654
Test: make RunSettingsRoboTests

tests/robotests/src/com/android/settings/notification/VolumeSeekBarPreferenceTest.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2017 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.notification;
+
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.Mockito.doCallRealMethod;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.content.Context;
+import android.media.AudioManager;
+
+import com.android.settings.TestConfig;
+import com.android.settings.testutils.SettingsRobolectricTestRunner;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.annotation.Config;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+public class VolumeSeekBarPreferenceTest {
+
+    @Mock
+    private AudioManager mAudioManager;
+    @Mock
+    private VolumeSeekBarPreference mPreference;
+    @Mock
+    private Context mContext;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        when(mContext.getSystemService(Context.AUDIO_SERVICE)).thenReturn(mAudioManager);
+        mPreference.mAudioManager = mAudioManager;
+    }
+
+    @Test
+    public void setStream_shouldSetMaxAndProgress() {
+        final int stream = 5;
+        final int max = 17;
+        final int progress = 4;
+        when(mAudioManager.getStreamMaxVolume(stream)).thenReturn(max);
+        when(mAudioManager.getStreamVolume(stream)).thenReturn(progress);
+        doCallRealMethod().when(mPreference).setStream(anyInt());
+
+        mPreference.setStream(stream);
+
+        verify(mPreference).setMax(max);
+        verify(mPreference).setProgress(progress);
+    }
+
+}