zbd: Support finishing zones on Android

zbd: Support finishing zones on Android

BLKFINISHZONE is missing from older versions of the Android NDK header
files. Hence, define BLKFINISHZONE if it has not been defined and detect
at runtime whether or not the kernel supports finishing zones.

Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230705212915.3373438-1-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>