LAVA: Increase monitor timeout limitation to 15 mins

Under heavy loads from pipeline, LAVA jobs take longder to execute.
Jobs are likely to reach timeout without any failure occurs.
Increase monitor timeout limitation to avoid such failures.

Signed-off-by: Xinyu Zhang <xinyu.zhang@arm.com>
Change-Id: I367a2db05fe4c9081b47fda284b358873eb38923
1 file changed