Update Kubernetes service pod spec and fix batch service test

- K8s Service: Update Kata container job spec with hostNetwork: True, HOST_UID=1337, capabilities: ALL, and standardized volume size. Skip default credential loading if K8S_E2E env var is set.
- K8s Tests: Update unit tests to verify spec generation and mock correctly. Patch _load_gke_credentials in unit tests to avoid default credential errors. Update e2e tests to verify job Running status instead of completion to avoid timeouts with default command. Skip e2e test if K8S_E2E env var is not set.
- Local Tests: Update kubernetes e2e test script with correct filename.
- Batch Service Test: Fix mock return value to be a Job object to resolve AttributeError.
- Deps: Add google-api-python-client, aiohttp, and google-cloud libs to root Pipfile for e2e tests.

Author: javanlacerda

src/clusterfuzz/_internal/datastore/ndb_init.py

@@ -51,16 +51,21 @@ def context():
     # multiprocessing.set_start_method to not fork.
     context_module._state.context = None  # pylint: disable=protected-access
 
-  with _client().context() as ndb_context:
-    # Disable NDB caching, as NDB on GCE VMs do not use memcache and therefore
-    # can't invalidate the memcache cache.
-    ndb_context.set_memcache_policy(False)
+  current_context = context_module.get_context(False)
+  if current_context:
+    yield current_context
 
-    # Disable the in-context cache, as it can use up a lot of memory for
-    # longer running tasks such as cron jobs.
-    ndb_context.set_cache_policy(False)
+  else:
+    with _client().context() as ndb_context:
+      # Disable NDB caching, as NDB on GCE VMs do not use memcache and therefore
+      # can't invalidate the memcache cache.
+      ndb_context.set_memcache_policy(False)
 
-    yield ndb_context
+      # Disable the in-context cache, as it can use up a lot of memory for
+      # longer running tasks such as cron jobs.
+      ndb_context.set_cache_policy(False)
+
+      yield ndb_context
 
 
 def thread_wrapper(func):

src/clusterfuzz/_internal/tests/core/k8s/k8s_service_test.py

@@ -27,6 +27,12 @@ class KubernetesServiceTest(unittest.TestCase):
   """Tests for the KubernetesService class."""
 
   def setUp(self):
+    patcher = mock.patch(
+        'clusterfuzz._internal.k8s.service.KubernetesService._load_gke_credentials'
+    )
+    self.addCleanup(patcher.stop)
+    self.mock_load_gke = patcher.start()
+
     data_types.Job(name='job1', platform='LINUX').put()
     data_types.Job(
         name='job2', platform='LINUX',

src/clusterfuzz/_internal/tests/core/kubernetes/kubernetes_test.py

@@ -32,6 +32,7 @@ class KubernetesJobClientTest(unittest.TestCase):
 
   def setUp(self):
     helpers.patch(self, [
+        'clusterfuzz._internal.k8s.service.KubernetesService._load_gke_credentials',
         'kubernetes.config.load_kube_config',
         'kubernetes.client.CoreV1Api',
         'kubernetes.client.BatchV1Api',