Improve "software/kvm/test: Wait long when big images are downloaded"

Wait even longer, as in some environments downloading big files takes a lot
of time which can lead to unstable test results.

Note: On fast environments the max won't be reached, so in such case the test
      speed won't be affected.

software/kvm/test/test.py

@@ -250,7 +250,7 @@ class TestAccessDefaultBootstrap(MonitorAccessMixin, InstanceTestCase):
   __partition_reference__ = 'adb'
   expected_partition_with_monitor_base_url_count = 1
   # as few gigabytes are being downloaded, wait a bit longer
-  instance_max_retry = 40
+  instance_max_retry = 100
 
   @classmethod
   def getInstanceParameterDict(cls):
@@ -347,7 +347,7 @@ class TestAccessKvmClusterBootstrap(MonitorAccessMixin, InstanceTestCase):
   __partition_reference__ = 'akcb'
   expected_partition_with_monitor_base_url_count = 3
   # as few gigabytes are being downloaded, wait a bit longer
-  instance_max_retry = 40
+  instance_max_retry = 100
 
   @classmethod
   def getInstanceSoftwareType(cls):