upgrade target to API level 28
upgrade target to API level 28

Signed-off-by: Jean-Tiare Le Bigot <0857133ffcd232122dc51ad55bf5fcc9d60af5d3@yadutaf.fr>

HackMyChurch/aelf-dailyreadings,HackMyChurch/aelf-dailyreadings,HackMyChurch/aelf-dailyreadings,HackMyChurch/aelf-dailyreadings,HackMyChurch/aelf-dailyreadings