Use Launcher.getLauncher(Context) instead of type-casting.

Bug: 32010039
Change-Id: Icb80d3e547a706740b84df2cb80f99e4a7f81c43
diff --git a/src/com/android/launcher3/Hotseat.java b/src/com/android/launcher3/Hotseat.java
index f9424d4..0fbbc19 100644
--- a/src/com/android/launcher3/Hotseat.java
+++ b/src/com/android/launcher3/Hotseat.java
@@ -67,7 +67,7 @@
 
     public Hotseat(Context context, AttributeSet attrs, int defStyle) {
         super(context, attrs, defStyle);
-        mLauncher = (Launcher) context;
+        mLauncher = Launcher.getLauncher(context);
         mHasVerticalHotseat = mLauncher.getDeviceProfile().isVerticalBarLayout();
         mBackgroundColor = ColorUtils.setAlphaComponent(
                 ContextCompat.getColor(context, R.color.all_apps_container_color), 0);