e2e: retry OLM uninstall

It failed at least once with:

    + /mnt/workspace/pmem-csi_PR-1054/_work/bin/operator-sdk olm uninstall
    time="2021-12-08T13:05:39Z" level=info msg="Fetching CRDs for version \"0.18.3\""
    time="2021-12-08T13:05:39Z" level=info msg="Fetching resources for resolved version \"v0.18.3\""
    time="2021-12-08T13:05:44Z" level=fatal msg="Failed to uninstall OLM: failed to get resources: failed to fetch CRDs: request failed: failed GET 'https://github.com/operator-framework/operator-lifecycle-manager/releases/download/v0.18.3/crds.yaml': unexpected status code 503, expected 200: \ufeff<?xml version=\"1.0\" encoding=\"utf-8\"?><Error><Code>ServerBusy</Code><Message>Egress is over the account limit.\nRequestId:55167efb-b01e-006c-4f34-ecc9f2000000\nTime:2021-12-08T13:05:44.6418446Z</Message></Error>"

test/start-stop-olm.sh

@@ -98,5 +98,13 @@ if [ $cmd == install ]; then
 elif [ $status -ne 0 ]; then
     echo "No running OLM found."
 else
-    ${BIN_DIR}/operator-sdk olm uninstall
+    attempt=0
+    while ! ${BIN_DIR}/operator-sdk olm uninstall;  do
+        if [ "$attempt" -ge 5 ]; then
+            echo "Giving up. Current status is:"
+            ${KUBECTL} get all -n olm
+            exit 1
+        fi
+        attempt=$((attempt + 1))
+    done
 fi