add retry in nested container tests

Author: bitoku

test/extended/testdata/bindata.go

@@ -1,9 +1,9 @@
 #!/usr/bin/env bash
 
 mkdir -p serial-junit
-PODMAN=$(pwd)/bin/podman bats -T --report-formatter junit -o serial-junit --filter-tags '!ci:parallel' test/system/ || touch fail
+PODMAN=$(pwd)/bin/podman BATS_TEST_RETRIES=3 bats -T --report-formatter junit -o serial-junit --filter-tags '!ci:parallel' test/system/ || touch fail
 mkdir -p parallel-junit
-PODMAN=$(pwd)/bin/podman bats -T --report-formatter junit -o parallel-junit --filter-tags ci:parallel -j $(nproc) test/system/ || touch fail
+PODMAN=$(pwd)/bin/podman BATS_TEST_RETRIES=3 bats -T --report-formatter junit -o parallel-junit --filter-tags ci:parallel -j $(nproc) test/system/ || touch fail
 touch done
 echo "Finished running tests."
 # wait for the test results to be retrieved