add a 1 second sleep before begin install

Summary:
I was having a weird failure that I finally figured out: when
software source config runs then storage config, the 'begin_
installation' needle can match while the 'slide down from the
top' animation is still playing, and by the time os-autoinst
positions the cursor to click where the button was when the
match happened, it's moved down and we wind up clicking outside
the button area. So, wait a sec before clicking to avoid this.

Test Plan: Run the server_sata_multi test.

Reviewers: jskladan, garretraziel

Reviewed By: garretraziel

Subscribers: tflink

Differential Revision: https://phab.qadevel.cloud.fedoraproject.org/D464

tests/_do_install_and_reboot.pm

@@ -7,6 +7,10 @@ sub run {
     assert_screen "anaconda_main_hub", 300; #
 
     # Begin installation
+    # Sometimes, the 'slide in from the top' animation messes with
+    # this - by the time we click the button isn't where it was any
+    # more. So wait a sec just in case.
+    sleep 1;
     assert_and_click "anaconda_main_hub_begin_installation";
 
     # Set root password