Merge pull request os-autoinst#20230 from jlausuch/slm_skip_boot_needle

Enhance disk_boot for SLMicro

tests/microos/disk_boot.pm

@@ -20,7 +20,9 @@ sub run {
     # default timeout in grub2 is set to 10s
     # Sometimes, machines tend to stall when trying to match grub2
     # this leads to test failures because openQA does not assert grub2 properly
-    if ((is_aarch64 || is_sle_micro('>=6.0')) && !main_micro_alp::is_dvd()) {
+    # KEEP_GRUB_TIMEOUT=0 will force the grub needle to match, useful when booting
+    # pre-configured images with disabled timeout. See opensusebasetest::handle_grub
+    if ((is_aarch64 || is_sle_micro('>=6.0')) && get_var('KEEP_GRUB_TIMEOUT', '1') && !main_micro_alp::is_dvd()) {
         shift->wait_boot_past_bootloader(textmode => 1);
     } else {
         shift->wait_boot(bootloader_time => 300);