Fix failing test due to recent change in transaction propagation (#10006)

PR #9890 may have introduced a problem.
There are tests that use MULTI-EXEC to make sure two BGSAVE / BGREWRITEAOF are executed together.
But now it's not valid to run run commands that create a snapshot inside a transaction (gonna be blocked soon)
This PR modifies the test not to rely on MULTI-EXEC.

Co-authored-by: Oran Agra <oran@redislabs.com>

tests/unit/aofrw.tcl

@@ -179,28 +179,28 @@ start_server {tags {"aofrw external:skip"} overrides {aof-use-rdb-preamble no}}
     }
 
     test {BGREWRITEAOF is delayed if BGSAVE is in progress} {
-        r multi
+        r flushall
+        r set k v
+        r config set rdb-key-save-delay 10000000
         r bgsave
-        r bgrewriteaof
-        r info persistence
-        set res [r exec]
-        assert_match {*scheduled*} [lindex $res 1]
-        assert_match {*aof_rewrite_scheduled:1*} [lindex $res 2]
-        while {[string match {*aof_rewrite_scheduled:1*} [r info persistence]]} {
+        assert_match {*scheduled*} [r bgrewriteaof]
+        assert_equal [s aof_rewrite_scheduled] 1
+        r config set rdb-key-save-delay 0
+        catch {exec kill -9 [get_child_pid 0]}
+        while {[s aof_rewrite_scheduled] eq 1} {
             after 100
         }
     }
 
     test {BGREWRITEAOF is refused if already in progress} {
+        r config set aof-use-rdb-preamble yes
+        r config set rdb-key-save-delay 10000000
         catch {
-            r multi
             r bgrewriteaof
             r bgrewriteaof
-            r exec
         } e
         assert_match {*ERR*already*} $e
-        while {[string match {*aof_rewrite_scheduled:1*} [r info persistence]]} {
-            after 100
-        }
+        r config set rdb-key-save-delay 0
+        catch {exec kill -9 [get_child_pid 0]}
     }
 }