sepolicy: add read of sf_lcd_density_prop for app domain.

ro.sf.lcd_density. allows OEMs to set density of respective panels.
This property is read at various places including SF,UI framework,
apps etc .. Primarily all the places where density matters for
content generation and test cases.

Change-Id: Icb30fa256ba29321b7d53f4b43b81be1a32e7fd8
1 file changed