Themes: Allow Permission Icons to be fully themed

This removes the forced @android:color/black tint on the permission
icons during app sideload through PackageInstaller.

These icons are able to be changed through framework XMLs, but this line
forces a black tint (invisible on dark themes) on the icons. Let's
remove this.

Change-Id: I31eb5021a6d297997dbba156f98cbf47f2102b6c