android/client: Define Android version for host
android/client: Define Android version for host

This patch defines PLATFORM_SDK_VERSION like it is handled in
Android.mk. This value corresponds to current copy of headers
from Android committed to bluez.

ComputeCycles/bluez,pkarasev3/bluez,mapfau/bluez,silent-snowman/bluez,pkarasev3/bluez,pstglia/external-bluetooth-bluez,pstglia/external-bluetooth-bluez,mapfau/bluez,silent-snowman/bluez,pstglia/external-bluetooth-bluez,silent-snowman/bluez,ComputeCycles/bluez,pkarasev3/bluez,pkarasev3/bluez,mapfau/bluez,pstglia/external-bluetooth-bluez,mapfau/bluez,silent-snowman/bluez,ComputeCycles/bluez,ComputeCycles/bluez