Build host coordination block for commands after vkQueueSubmit. (#220)
Build host coordination block for commands after vkQueueSubmit. (#220)

- So far when GroupBySubmission is toggled on, we do command grouping
 for the commands between two adjacent vkQueueSubmit commands. We should
 do another grouping for the commands after the last vkQueueSubmit in a
 frame as well.
 - Remove unused local variable `count`.
 - Bug: b/150944398.
google/agi,google/agi,google/agi,google/agi,google/agi,google/agi,google/agi,google/agi