Fix python postcommit

Author: damccorm

.github/trigger_files/beam_PostCommit_Python.json

@@ -1,5 +1,5 @@
 {
   "comment": "Modify this file in a trivial way to cause this test suite to run.",
-  "modification": 33
+  "modification": 34
 }
 

sdks/python/test-suites/direct/common.gradle

@@ -185,6 +185,12 @@ tasks.register("hdfsIntegrationTest") {
   // needs generated srcs in sdks/python
   dependsOn ':sdks:python:sdist'
 
+  doFirst {
+      exec {
+        executable 'sh'
+        args '-c', ". ${envdir}/bin/activate && pip install hdfs>=2.1.0,<3.0.0"
+      }
+    }
   doLast {
     exec {
       executable 'sh'