Misc GAR fixes

- Use colorPrimary for EntityHeader background.
- Update data usage header text to be 87% black.

Change-Id: Ic361155d7cd36a2f1cca96e918af0e3855fb8ced
Fixes: 79773433
Test: robotests
Test: visual

src/com/android/settings/widget/EntityHeaderController.java

@@ -31,9 +31,11 @@ import android.graphics.drawable.ColorDrawable;
 import android.graphics.drawable.Drawable;
 import android.os.Bundle;
 import android.os.UserHandle;
+
 import androidx.annotation.IntDef;
 import androidx.annotation.VisibleForTesting;
 import androidx.recyclerview.widget.RecyclerView;
+
 import android.text.TextUtils;
 import android.util.IconDrawableFactory;
 import android.util.Log;