Drop helmv2 database after Armada removal

This change adds a function to the Armada removal script that runs
during platform upgrades giving it the ability to remove the helmv2
database if no Armada apps are present.

Helm v2 is not supported anymore so its database should be dropped
alongside the removal of Armada as no other platform components will
make use of it.

Test Plan:
PASS: build-pkgs && build-image
PASS: SX upgrade from stx-8 to master
      Check if helmv2 database was removed

Story: 48480
Task: 2010560
Change-Id: I3c6489643bcf608893b8715f4d3c4a45c72e03ec
Signed-off-by: Igor Soares <Igor.PiresSoares@windriver.com>

controllerconfig/controllerconfig/upgrade-scripts/76-remove-armada-if-unused.py

@@ -336,6 +336,39 @@ def remove_docker_images():
     return True
 
 
+def drop_helm_v2_database():
+    """
+    Drop Helm v2 PostgreSQL database since it is not needed
+    after Armada removal.
+    """
+
+    env = os.environ.copy()
+    drop_database = subprocess.Popen(
+        ['sudo', '-u', 'postgres',
+         'psql', '-c',
+         'DROP DATABASE IF EXISTS helmv2'],
+        env=env, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+        universal_newlines=True)
+    timer = threading.Timer(20, kill_process_and_descendants, [drop_database])
+
+    try:
+        timer.start()
+        _, err = drop_database.communicate()
+        if drop_database.returncode != 0 and err:
+            LOG.exception(err)
+            return False
+        elif drop_database.returncode != 0:
+            LOG.error("Unknown error while dropping helmv2 database")
+            return False
+    except Exception as e:
+        LOG.exception("Failed to drop helmv2 database: %s" % e)
+        return False
+    finally:
+        timer.cancel()
+
+    return True
+
+
 def main():
 
     if len(sys.argv) != 4:
@@ -367,6 +400,9 @@ def main():
             if not remove_docker_images():
                 return 1
 
+            if not drop_helm_v2_database():
+                return 1
+
             LOG.info("Armada removed.")
         except Exception as e:
             print(e)