Update System UI to use theme colors.

Instead of using hardcoded values, use colorPrimary, colorAccent, etc
to style system UI. Required setting a theme on several views to
get the proper accent color in the right place.

Deletes a lot of hard-coded colors from the app.
Deletes an unused view: StatusBarHeaderView

BUG: 28625050
BUG: 29003410
BUG: 28625105
Change-Id: I46cd8eba7cf5afdab53c7882aa4aac5af46772a9
diff --git a/packages/SystemUI/src/com/android/systemui/volume/VolumeDialog.java b/packages/SystemUI/src/com/android/systemui/volume/VolumeDialog.java
index 1973e05..5b558a6 100644
--- a/packages/SystemUI/src/com/android/systemui/volume/VolumeDialog.java
+++ b/packages/SystemUI/src/com/android/systemui/volume/VolumeDialog.java
@@ -68,6 +68,7 @@
 import android.widget.SeekBar.OnSeekBarChangeListener;
 import android.widget.TextView;
 
+import com.android.settingslib.Utils;
 import com.android.systemui.R;
 import com.android.systemui.statusbar.policy.ZenModeController;
 import com.android.systemui.tuner.TunerService;
@@ -152,7 +153,7 @@
         mKeyguard = (KeyguardManager) context.getSystemService(Context.KEYGUARD_SERVICE);
         mAudioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
         mAccessibilityMgr = (AccessibilityManager) mContext.getSystemService(Context.ACCESSIBILITY_SERVICE);
-        mActiveSliderTint = loadColorStateList(R.color.system_accent_color);
+        mActiveSliderTint = ColorStateList.valueOf(Utils.getColorAccent(mContext));
         mInactiveSliderTint = loadColorStateList(R.color.volume_slider_inactive);
 
         initDialog();