Switch Tuner to support prefs (and some improvements)

Change-Id: I2ef62c0c56d4af69f9f34e1cfd297999d59b7da6
diff --git a/packages/SystemUI/proguard.flags b/packages/SystemUI/proguard.flags
index 75e7959..6a10c2c 100644
--- a/packages/SystemUI/proguard.flags
+++ b/packages/SystemUI/proguard.flags
@@ -27,3 +27,9 @@
     public float getTaskProgress();
     public void setTaskProgress(float);
 }
+
+-keepclasseswithmembers class * {
+    public <init>(android.content.Context, android.util.AttributeSet);
+}
+
+-keep class ** extends android.support.v14.preference.PreferenceFragment