tests: stabilization: reattempt to add disks in case 'vda' was not ch…

…osen

Sometimes the kernel does not pick 'vda' for the first attached disk but 'vdb' directly. This is
seeminglyl some race condition but it heavily affects our tests runs
since 'vda' is often hardcoded. Let's attempt to eject and re-add disks
if this happens.

test/anacondalib.py

@@ -117,10 +117,14 @@ def setUp(self):
         # Wait for minimum /dev/vda to be detected before proceeding
         try:
             wait(lambda: "vda" in m.execute("ls /dev"), tries=5, delay=5)
-        except Error as e:
+        except Error:
             print("vda not detected")
             print(m.execute("lsblk"))
-            raise e
+            self.removeAllDisks()
+            s.udevadm_settle()
+            self.addAllDisks()
+            s.udevadm_settle()
+            wait(lambda: "vda" in m.execute("ls /dev"), tries=5, delay=5)
 
         self.partition_disk()